St. Mary’s Church in Lytchett Matravers in Dorset dates from the late 12th century. There was a village built around the church in mediaeval times and a manor house was built near the church. The church and manor house were connected to each other by means of an underground tunnel. The manor house was demolished and another building erected in the 19th century.
The purpose of the tunnel is currently unknown, it may have been for smuggling purposes or was possibly a tunnel to facilitate a Roman Catholic priest to escape from the church after performing mass post-Reformation, or may have been for some other purpose.
Several parishioners who have been involved in the church over many decades, recall seeing some younger members of the choir exploring down the tunnel in the 1950s. After this, the tunnel was then sealed off, and the exact location almost forgotten, but the existence of the tunnel is not in doubt.
The objective was to find the tunnel again, but using non-invasive techniques.
EDAS (East Dorset Antiquarian Society) supported the investigations with a GPR (Ground Penetrating Radar) survey. An area of 30 by 15 m was surveyed in the garden of the manor, which appears to show the tunnel location between the churchyard and the manor house.
To help investigations in the churchyard, BACAS performed an ERT (Electrical Resistivity Tomography) survey. The results appear to show the tunnel’s location at either end, although there is some location discrepancy by the church.