The Barracks is a secure residential compound on the Island comprising houses and other surface buildings with electricity and water service, plus an unknown number of underground facilities. Originally constructed by the DHARMA Initiative, the Others took control of them after the Purge, using the compound as their home and base of operations on the Island.
The Others abandoned the Barracks in 2004 in anticipation of the arrival of the mercenary team sent by Charles Widmore. When the survivors of Oceanic Flight 815 split into two groups, Locke's group temporarily resided in the Barracks. Since then, the Barracks had been abandoned.
The Barracks are located directly north of the Pearl, as shown on Ben's radio tower map and Kate's map.