Teleferico (cable car) in SD was not built for tourists, but as the public transport service for those who live in barrios (poor neighborhoods). This is a totally safe way to observe barrios from above. You'll see how people live, their schools, small churches, colmados (local stores), tiny streets, rivers and bridges. Teleferico is clean and very cheap (less than a dollar for a round trip). It’s the best way to see the other face of one of the most contrasting capitals of the world.