Tiahuanaco, also known as Tiwanaku sits 12,500 feet above sea-level in the heart of the Bolivian Andes. It is located some 15 miles from the shores of Lake Titicaca. Some scholars have hypothesized that the place name is a corruption of the Aymaran "taypikala", meaning "stone in the center", a possible reference to the fact that the city may have been the spiritual center of an ancient empire.
Recent satellite based studies have suggested that the three valleys of in the area had a carrying capacity between 285 thousand and nearly 1.5 million people. The civilization that existed here may have its roots as far back as 1500 BC, and it lasted until about 1400 AD, when a changing climate began to favor the emergent Inca Empire.
Today, little is known about the culture that built this city. They left behind no written records, and by the time the Conquistadors came into the area the city was already in ruins. However, today it is a fascinating place to visit, popular with spiritual seekers, contemporary travelers and historical buffs. Most of the main sites can be seen on a day tour, but you might want to consider giving it a bit more time to really get to know the place.