A 3km walk northeast along the shoreline from the end of Calles Junín or Hugo Ballivián leads to the community-run colonial manor known as Kusijata, where there's a small, dusty archaeological display. If you can see in the semi-dark - the lights are not turned on - seek out the long-deceased human sitting in an upright fetal position, as he was buried. A young caretaker should chase after you with the key as you walk up the hill; otherwise ask around.
