I’ve spent two summers in Copacabana as part of an archaeological field school offered through my anthropology department. Because of this, I’ve had the opportunity to visit most of the archaeological sites along the Copacabana Peninsula in Bolivia. This area has been populated since the Preceramic period (5000-1500 BCE), and it houses quite a few sites which are still considered sacred to the local population. There are a number of sunken temples in the area which are associated with a pre-Tiwanaku tradition known as the Yaya-Mama. These temples are located in various parts of the peninsula, generally on top of hills outside of modern villages. Three of these sites have been partially excavated, but the fourth, located in the village of Chi’si, has been fully excavated and restored to its original form during the early 1990s (the project was funded by National Geographic and an article can be found in the March 1992 edition in Spanish). This temple is roughy a thousand years older than Tiwanaku, and is definitely a predecessor to the sunken temple found in front of the Kalasasaya temple at that site. Research conducted on the remains found at the site have indicated artificial cranial modification and trepanation occurred at the site for over a thousand years (see this article in Forbes). This site is open for visitors, and a museum should be open sometime in the near future with the items from the excavations. For anyone visiting the area who is really into archaeology, it’s a worthwhile visit, especially once the museum is ready for visitors.