Ciudad Perdida (The Lost City) is one of the wonders of Colombia and South America and one of South America's most popular trekking destinations. The trek is 44 km/27 mi round trip, and takes 4 days to complete. The hike is strenuous because of the heat, humidity, mud, bugs, and steep ascents and descents. Ciudad Perdida (Known locally by its indigenous name of Teyuna) has been founded around 800 CE, and abandoned after the Spanish colonization. Rediscovered in the 1970s, and up to today only small part of the area has been uncovered.