I am now visiting La Paz, Bolivia. The city is on the edge of the altiplano, starting on the plain at 13000 feet and running down through a connected series of valleys. The result is amazing beauty. Traveling between neighborhoods often means seeing marvelous vistas. The snow-capped mountain Illimani can also be seen from much of the city.
On my next-to-last day in La Paz, I went to see the ancient ruins of Tiwanaku, and Lake Titicaca. My hosts and I hired a taxi for the whole day--it was the only way to go. When we got to Tiwanaku, we took a little too long eating lunch, which forced us to hurry a bit visiting the ruins and the museum.