Inside the Universidad Austral de Chile on Teja Island hangs a Foucault pendulum — a heavy weight suspended on a long wire that swings slowly and continuously, knocking down small pins arranged in a circle around its base as the Earth's rotation causes the plane of its swing to gradually shift. The Valdivia pendulum is one of the largest in South America, with a wire length of about 19 metres, and watching it knock down successive pins as the Earth turns beneath it is one of those rare moments when a physical fact about the universe becomes viscerally real rather than abstractly known.
The pendulum was installed in the university's main building in the 1980s and is accessible during university opening hours. The building is on the Teja Island campus, a short walk from the riverside museums. The university itself is worth seeing — its wooded campus, established in 1954, has a pleasant quality and the river views from its northern edge are some of the best in the city.