The Vault inside Mt. Zion Cemetery
Until the abolition of slavery, Mt. Zion served as one of the stations on the Underground Railroad. The vault in the Old Methodist Burying Ground (Mt. Zion Cemetery) was used as a hideout for runaway slaves until their passage north could be arranged. They hid in the vault among the bodies awaiting burial.
(Source: Black Georgetown Remembered)
As part of the Underground Railroad, The Vault has been designated an UNESCO Site of Memory. The designation places The Vault on an international registry commemorating slavery and the slave trade.