On the eastern edge of the hillfort is St Martin’s Chapel which dates from the 13th century. By the end of the 16th century its use as a chapel had lapsed and it became a barn. It is now an empty shell but is preserved as a scheduled ancient monument. The chapel is signed off the road and is reached by an unmetalled track. Inside the chapel is a storyboard explaining the building.
This delightful chapel was built as a chapel of ease - in other words it was more convenient. It was originally constructed by the lord of Chisbury Manor not only to assert his high social status but also to enable the household of the manor, as well as local people, to attend services and pay their taxes without having to travel to the parish church at Great Bedwyn.
The building ceased to be used as a consecrated chapel in 1547 at the time of the Reformation, and has been used as a barn for the past three centuries. The building is a pretty thatched and flint-walled construction, whose original function is still clearly visible today.
There are two vertical lines within the plaster of the side walls that mark where the rood-screen – a timber partition surmounted by a cross – once separated the altar from the nave. There is also a red cross. Crosses were painted on the walls of a church during the consecration ceremony, marking the religious status of the building.