The monastery's drain, an imposing stone vaulted construction, was rediscovered in the early 1990s and a wealth of fascinating historical detail has been found in the silt at the bottom of the drain.
Some of the items from the drain are currently on display in the Sacristy exhibition. As well as the slate music mentioned above, interesting items discovered include dice and gaming tokens, tuning pegs for musical instruments and lead seals from cloth which show that the abbey imported cloth from many parts of Europe including the Netherlands and Italy.