In 1887 the Scottish Benedictine Abbey of Fort Augustus, south of Loch Ness, received by Pope Leo XIII a rich collection of relics of various saints. In order to give a proper place for storage and worship of these relics, the community decided to open a new reliquary chapel by reusing and redecorating an underground room (5 x 4 metres), previously used as a service room and then abandoned. The place was structured and decorated in the style of the Roman catacombs, modelled by members of the Fort Augustus community, Father Luke Cary-Elwies and Father Lawrence Mann. 

The architectural structure aimed to recall the cubicles of the early-Christian Roman catacombs. Some openings in the side walls reminded arcosolia and loculi, all intended to contain the relics. The decoration served the same purpose: the room was fully decorated with many scenes inspired by the paintings in the catacombs: among them, the banquet scene from Callisto and images of standing saints in style of late-antique/early-medieval Roman style. The vaulted ceiling bore the classic system of red and green lines emphasising the hypogeal architecture and there were figures of orantes on the vault corners. A christogram is placed in the keystone and the altar is built recalling early-Chirstian style.