Incarceration is one of the major industries in the Adirondacks. There are two dozen prisons in the region, including several that are within the blue line of the park. The largest of these is the Clinton State Prison in downtown Dannemora, near the northeast corner of the park. Clinton is the largest maximum security prison in the state, with around 1,000 employees, and close to 3,000 inmates. Originally built in 1844 to supply inmates to work the iron mines at Lyon Mountain, the prison was soon expanded. The 60-foot-high walls, built in 1887, dominate the village. Next to it is a second complex, in a former state asylum.