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.

The most interesting finds come from the areas nearest the openings and must have been deposited in the mid-16th century.

They include bronze dress or "wimple" pins, which were indispensable items for nuns.

Several hundred fragments of floor tile were found, most of which are from the local Nash Hill Kiln site and date from the 13th century.

Painted glass window fragments, a lead pilgrim's ampulla, bronze shears and a 14th century book clasp were also found and are being conserved.

David Formby, National Trust custodian of Lacock Abbey, said: "We undertook these excavations to ease problems of rising damp in the building by undoing the work of Sharrington's 16th century builders, who used the drain as a skip."

Archaeologist Jane Harcourt, who managed the project for the National Trust, said: "What was viewed as rubbish in the 16th century is of great interest to us in the 21st century.

"We have found 300 bronze dress pins which would have been essential for nuns in the 13th century to secure their wimples and which were used by all women in the 14th and 15th centuries." ..SUPL: