Raven Rock

 is the Enclave's main base of operation in 2277. It can be found in the northwestern part of the Capital Wasteland.

Apperances
 only appears in Fallout 3.

Behind the scenes
Raven Rock Mountain Complex is a real-world government complex that became operational in 1953.

Incidentally, a settlement of the same name also appeared in one of Bethesda's earlier games; the Morrowind expansion pack Bloodmoon.