A vast monastic drain, dating from about 1230, has been unblocked at a historic abbey, the National Trust has revealed.

The drain was infilled in the 16th century and the work has uncovered a builder's dump full of fascinating archaeology.

The Trust carried out excavations of the monastic drain at Lacock Abbey in Wiltshire to help understand the present-day problems with damp in the building, which includes famous medieval cloisters.

The dig, carried out by hand, removed 64 tonnes of debris used as infill by William Sharrington, who bought the abbey in the 16th century after the Dissolution.

The drain originally served the reredorter, which were the lavatories in the 13th century nunnery and which functioned as the main sewer for the abbey and would have originally run off into the river.