Empire Quarry, south of Bloomington on the edge of the Hoosier National Forest, is an abandoned limestone quarry that supplied stone for the Empire State Building in the early 1930s. The quarry closed decades ago and has been slowly reclaimed by nature: the pits have filled with green water, the cut-stone walls are draped with moss, and a forest is growing through the machinery platforms.
The site is technically on private property but has long been used by local hikers, rock climbers, and — because of its dramatic graffiti-covered walls and post-industrial atmosphere — artists and photographers. It appears on maps as a hiking destination accessible via trails from the nearby Hoosier National Forest. The scale of the excavation becomes apparent when you stand at the edge and look down — these are not small holes but massive industrial operations that chewed through hundreds of metres of solid rock.
Call ahead if you plan to visit, as access arrangements can change. The Indiana Limestone Heritage Trail, a driving route connecting several operating and historic quarries in the region, includes the area and provides good context for what you're seeing.