Moored on the Valdivia River a short walk from the city centre, the Chilean submarine O'Brien is an Oberon-class submarine that served in the Chilean Navy from 1976 to 2004 and is now preserved as a museum ship. At over 90 metres long, it is one of the largest museum exhibits in Chile. Visitors can tour the interior, which is largely intact — the cramped torpedo room, the control room with its original instruments, the crew quarters and engine spaces that give a vivid sense of the extreme conditions of submarine service.
The O'Brien (named for the Irish-Chilean independence war hero Bernardo O'Higgins's naval commander) was built in Britain under the Oberon programme and was one of the most capable conventional submarines in Latin America during the Cold War period. The museum context is modest — most information is in Spanish — but the experience of moving through the interior of an operational Cold War submarine is absorbing in itself. The riverside setting, with the forested Teja Island across the water, is attractive. Open daily; admission charged.