La Brea Pits - the graveyard of prehistoric saber-tooth cats and dire wolves - is the world's only active, urban Ice Age excavation site and is located right in the middle of downtown Los Angeles. Part of Museum Row on Wilshire Boulevard's Miracle Mile, the George C. Page Museums displays fossils, skeletons and models of pre-historic animals in the 23-acre (9 ha) Hancock Park, established in 1924 for that purpose. The Observation Pit, a mid-century building which closed in the 1990s, recently reopened and is part of the museum's new Excavator Tour, free with general admission.