A Revolution in Public Transportation Medellín and La Paz, two cities defined by their unique geographies, have turned their challenging landscapes into opportunities for innovative urban transportation solutions to improve mobility and tackle poverty reduction. While Medellin stretches linearly along a fertile tropical valley bounded by mountains, La Paz sits in a bowl-shaped valley amidst dramatic topography.  In both cities, poverty is concentrated in the inaccessible high-altitude neighborhoods, where makeshift settlements spread onto higher ground due to a lack of space. Meanwhile, employment opportunities, educational facilities, and healthcare access  are concentrated in the lower, wealthier areas. Medellín is home to 3 million residents living at around 1,500 meters above sea level, making it a perfect location for a mild, spring-like climate all year round. Towering tropical plants dominate parts of the wealthier neighborhoods, and a strong midday sun warms up the city’s many rooftops. La Paz, the highest capital city in the world at an elevation of 3,650 meters, has fewer than a million residents. However, when including the nearby city of El Alto, which sits at a breathless 4,000 meters, the total population exceeds 2 million. The higher areas are colder, with temperatures dropping 7 degrees Celsius for every 100 meters of ascent, which pushes wealthier populations to settle in the more temperate lower elevations.  El Alto houses the poorest residents on a flat altiplano, and its urban sprawl is only limited by a slowing pace of urbanization. At the city’s edge, buildings overlook a steep 600-meter drop to La Paz below. Remarkably, stairs wind up the steep walls of the precipice, leaving El Alto’s residents either exceptionally fit or nearly dead from the daily commute to the wealthier and more touristy La Paz. Medellín: Pioneering Urban Mobility Medellín, known as Colombia’s “City of Flowers,” has transformed its urban landscape with groundbreaking transportation solutions. Founded in 1616, the city grew rapidly in the late 19th century with the arrival of the railroad, promoting textile and agricultural industries. Despite a period of violence linked to drug cartels in the late 20th century, Medellín has reinvented itself through urban renewal. In 1995, Medellín introduced Colombia’s first elevated metro system and in 2004, pioneered the Metrocable, the world’s first public cable car network, connecting hillside neighborhoods to the city center. Operated by the Medellín Metro Network, these cabins travel at 18 km/h, easing the commute for up to 3,000 passengers per hour. The introduction of outdoor escalators in Comuna 13, a once-troubled area, have also improved access for residents living on steep hills. The area has since become a tourist destination, with colorful streets, music, bars, and restaurants, though not all residents welcome the change. Six cable car lines branch off from the main metro line into the heights on either side, reaching the once-isolated neighborhoods of Villa Sierra, La Aurora, Santo Domingo, Arví, Trece de Noviembre, and El Progreso. La Paz: Navigating the Heights La Paz presents even more challenges in infrastructure development than Medellín with its extreme elevations, rugged terrain, canyon, and distinct altitudinal zones. Arriving by bus from any southeastern cities via El Alto offers an unforgettable experience, as you descend along the twisting highway on the edge of the precipice, gazing into the bowl that cradles the city of La Paz. In 2014, La Paz inaugurated Mi Teleférico, the world’s longest and highest urban cable car network. This system revolutionized public transportation by connecting La Paz with its higher neighboring city of El Alto, reaching altitudes of up to 4,2000 meters. Mi Teleférico features several lines, each with its own color: orange and red, blue and celeste, white and silver (to start with the hardest to differentiate), café, purple, green, and yellow. Each line is well identified in the urban fabric with equally brightly colour-coded stations. La Paz’s cable car network not only connects previously inaccessible neighborhoods but also serves as an alternative to the metro system, given the city’s uneven terrain. Each line provides unique views and experiences: the Red, Purple, and Yellow Lines traverse the impressive divide between lower La Paz and higher El Alto, offering dramatic drops on the return trip. The White and Blue Lines travel above major boulevards in La Paz and El Alto respectively, providing comfortable views of city activities, traffic, and the lively Sunday market in El Alto. The Celeste Line winds through a canyon to reach the town center, while the Green Line extends from the southern part of La Paz to the lower-altitude Irpavi. Conclusion: An eco-friendly urban transport Medellín’s Metrocable and La Paz’s Mi Teleférico are prime examples of how innovative transportation systems can transform cities, boost mobility, and drive economic growth. In addition to alleviating traffic congestion, reducing travel time, and providing a safe, reliable, scenic, and eco-friendly mode of transportation, the cable car system does not emit any environmental or noise pollution. Small businesses and markets have flourished around the cable car stations, creating jobs and boosting local economies. Riding these megastructures, it is impressive how smoothly the system operates. The design allows passengers to board and disembark the cable cars without the system stopping, though transitioning between the moving platform and the stationary one can be a bit disorienting. During rush hours, assistance is always available, with staff stationed at each stop to ensure safety. Remarkably, even elderly Quechua women with their loads navigate the system with ease.

Oruro is dusty, elevated, and known for its mining and carnival. Although I was too early for the famous carnival of February, I got to experience another major event that should be added to the city’s attractions: the road workers’ strike.

Potosí rests on a barren central altiplano at nearly 4,100 metres in altitude, tormented by icy winds and arctic nights. Despite its remoteness, its centre is a frozen tableau of colonial architecture, with baroque frosted churches and convents reflecting a past explosion of opulence and indulgence. The old city is built on a slope that drops abruptly to the new city, and its streets are purposely designed to twist and curve to cut the wind. The thin air in these narrow streets is filled with a sense of sadness, echoing a tragic history. To the south looms Cerro Rico, a cone-shaped mountain stained by centuries of mining waste and perforated with so many mines that it threatens to collapse. This peculiar city owes its existence to the world’s largest silver deposit, nestled within Cerro Rico. In the early 16th century, after the conquistadors seized the immense treasure from the Incas, Potosí quickly became an imperial city and a vital industrial complex, producing about 60% of the world’s silver. In the 17th century, it even surpassed Paris in size and significance. While Cusco and Machu Picchu were the epicenters of the Incan empire, Potosí was the heart of the Spanish empire. The exploitation of the city’s minerals is believed to have fueled the economic development of Renaissance Europe. However, this wealth came at the cost of an estimated 8 million indigenous forced laborers and African slaves who died between 1545 and 1825. Although mining output began to decline in the early 19th century, the growing demand for tin (étain) in the 20th century, driven by the electronics industry, helped sustain the local economy. Since 2004, the number of ore processing plants has tripled, and many miners returned to the dim passageways to rework old silver mines for less valuable metals. The working conditions remain miserable as they were centuries ago, with silicosis—a deadly lung disease—and occasional cave-ins significantly reducing life expectancy. Yet, the miners earn a better living than early-career teachers and take great pride in their traditional line of work. Chewing a mouthful of essential coca leaves before entering the mines helps keep fatigue, hunger, and exhaustion at bay. However, the interior of the mountain is not as lifeless as it seems. Deep within the mines reigns El Tío, the Lord of the Underworld. El Tío is the Quechua pronunciation of “El Dios”, as the language lacks the “D” sound. Although the entity is derived from the God of Catholicism, it shares little resemblance with it. El Tío remains confined to the mines due to condemnation from the Catholic Church. Conversely, Christian symbols are not allowed inside the mines: the Underworld is El Tío’s domain. To appease this devil-like spirit, who is responsible for both protection and destruction, miners bring offerings like cigarettes, coca leaves, and pure alcohol to the many shrines within the mines.  Visiting the mines is not for the faint-hearted. Claustrophobia can be psychologically challenging, but the thin air mixed with dust and gases can make breathing difficult. The three-hour tour costs 130 bolivianos (18$US or 26$C) and includes two hours inside the mines with opportunities to talk to the miners at work. Due to the confined spaces, groups are limited to eight people. Our group consisted of six tourists, two young staff members from the tour agency responsible for our well-being, and an experienced guide. The tourists included a couple from Colombia, a Greek, a German, and a Swiss. Both the staff and the guide were familiar with the mining conditions and clearly enjoyed the trip, a sentiment not necessarily shared by us newcomers. No special provisions were made for tourist comfort, which, in a way, spared us from feeling patronized or pampered. As we had to roll in dust, fumes, and muddy water, we were equipped with overalls, jackets, boots, headlamps, and helmets to protect against frequent head bumps. After gearing up, we visited a miners’ shop to buy mandatory surgical masks and gifts for the miners: coca leaves, black-tobacco cigarettes, pure cane alcohol, carbonated drinks, and even dynamite sticks. Yes, dynamite. Despite cooperatives overseeing the operations, miners have to purchase their own equipment. A few minutes after entering the mine, we paused at the shrines to light a large cigarette for El Tío and pour alcohol on different parts of his body, as he and the supernatural forces are in charge of security down there. It seemed to work, as we avoided many dangers like the lack of breathable air, falling stones, and runaway trolleys. The pure alcohol that remained is mixed with water to create artisanal whisky. Although the entrance of the mines appears quite sturdy, with stone linings dating from the colonial era, it soon begins to deteriorate as we go deeper. With five centuries of tunnels digging, nearly 100 kilometers of underground passages, and numerous sinkholes (some up to 50 metres wide), shaken daily by explosions, the mountain has been officially deemed unstable and on the verge of collapsing since 2014.  Despite the entrance being over 4,000 metres above sea level, the temperature inside the mines can reach 40°C. The tunnels narrow, and the ceiling lowers as we progress, forcing us to bend sideways and sometimes crawl through connecting passages, stirring up dust and gases in the already thin and rancid air. After about an hour of walking and crunching through debris, I began to worry about the location of the nearest exits. To further test our trust, we descended to a lower level via a winding, narrow connecting passage that disturbingly narrowed to the size of a pipeline halfway down. However, the confidence of our guide kept us moving forward. No one in our group required assistance, but I could easily imagine the panic some might feel; apparently, every tour has one or two people who want to leave within the first 10 minutes. Up to 15,000 miners still work in Cerro Rico, including many children. More than 30 mining cooperatives serve as the main organizational structure for these miners.

Designed as a UNESCO World Heritage Site and renowned as Chile’s oldest port city, Valpo has a rich history dating back to the 16th century. Back then, it served as a major stop for ships traveling between the Atlantic and Pacific oceans. Today, the city stands as a cultural hub that attracts artists and art enthusiasts from around the world. Its urban layout is characterized by steep hills crisscrossed by colorful staircases and a series of historic funicular elevators. The journey by bus from Santiago to Valparaiso typically ranges from 1.5 to 2.5 hours, and numerous buses cover the 120 kilometers distance per day. A perfect city for strolling the streets, admiring the myriad artworks covering every vertical surface. Having stayed at various accommodations, I found Cerro Alegre and the Maki hostel on Urriola Street to be my favorite spot.

Mendoza is a unique desert town that strategically uses its proximity to the Andes to capture the melting glaciers and reshape its urban geography. Having endured the mosquito-rich tropical rains of southern Brazil during the austral summer, and more recently in Rosario, Argentina, I found Mendoza, a 12-hour drive away, surprisingly enchanting and refreshing. The break from constant humidity felt like a divine intervention, even though the temperature stubbornly remained at a scorching 34 degrees. There’s something unique about Mendoza beyond its more tolerable weather. Despite being a desert town, the streets remain lively and walkable even during the siesta hours. I have always wondered what makes a city attractive; in Mendoza, it struck me like a ton of grapes: the trees! These natural umbrellas not only create a livelihood amidst the stern concrete backdrop, but also drape the sidewalks and road pavement with a sparkling shade. Without these trees, walking the streets would be like strolling through an inferno. As you navigate the sidewalks, another particularity catches your eye, and your feet—the pathways are raised to accommodate the integration of canals. Not for rainwater management, mind you (as there is only 200 mm of rainfall per year), but to channel water from the melting Andean glaciers. This water nurtures not only the trees but also the vineyards that have become the lifeblood of Mendoza’s renowned wine industry. Nestled beneath the Cordillera, this ancient pit stop on the trading route now boasts nearly a million inhabitants. However, an 1860 earthquake flattened the city, giving urban designers carte blanche for a radical rebuilding. Along with five evenly distributed plazas serving as safe zones, the city features an innovative canal system, known as acequias, which uses controlled watering to nurture towering leafy trees from a different climate, making the cactus the odd one out. Mendoza’s unique blend of climates defies the stereotypical desert town aesthetic and demonstrates an artful utilization of natural geography to enhance human life. The houses embody a blend of desert aesthetics and Spanish influence, with their low-lying sloped roofs covered in tiles. Every window is adorned with shutters to protect against the intense sun rays and the occasional dust storms. What sets these homes apart, though, is the use of grilles along the lot lines instead of walls, serving as the primary security barrier and doubling as a dog house. Another colorful aspect of the city is the many fruit stalls offering a variety that breaks the equatorial monotony of green lemons, green oranges, and green squashes. Along with the long-missed sight of Granny Smith apples, yellow lemons, and strawberries, Mendoza throws another fruit layer to the mix with olives, green and red grapes, and peaches.