The Abbey is a location that never made the final release of Fallout 2. More info can be found on The Vault (English)
There are a few versions of this mod:
The orginal version was created by Skynet & ShadowBird [link]
Alternative Life mod contains a variant of the original release, many new quests have been added.
Skynet created an updated version which has been modified by Killap for the Killap's Fallout 2 Restoration Project.
Lich Created a parody mod called Abbey 2 in Polish.
The Alternative Life version is to be included in the MIB88 Megamod V2.3
With Alternative Life this mod included in Global mod