Abbey of the Sword

The Abbey of the Sword is a large temple to Tempus in Battledale, which is built atop a network of caverns leading to portals to the Underdark.

Game material refernces
A short description can be found on page 121 of the Forgotten Realms Campaign Setting.

An in depth description of the location can be found on pages 142-163 of Faiths and Pantheons.