A question frequently asked is ‘are there tunnels under Grantham town?’
The answer is, almost certainly not. It was thought that a tunnel ran from Greyfriars to St Wulfram’s Church. This, coincidentally, runs along a very similar line to the river Mowbeck, which is now culverted. The Mowbeck becomes very full at various times of the year and used to regularly flood adjacent houses, even as recently as the 1940s. Had there been a tunnel, it would almost certainly have been permanently under water.
During the demolition of old stone buildings in the town in the 1700s, many were razed to the ground and rebuilt of brick. The cellars were left intact and new buildings were built from the ground upwards. Cellars were sometimes continuous along the building line, with arches or doorways joining many properties together. This was the case along the High Street, and it may have given the impression of tunnels.
The basements are now separated by partition walls. These basements also have arches, with the old stone foundations and preparation slabs set into them. There are also meat hooks in the roof. The arches go a short distance under the road, which was obviously narrower at some time in the past. There are sealed coal chutes and stone stairs that go nowhere.
There was also a vaulted basement in a long-since demolished building on Market Place near Butcher’s Row, which was probably a cellar. A row of cottages once stretched out towards the west end of St Wulfram’s Church. They were demolished in Victorian times, but it appears that not all the cellars were filled in, because people in the town remember looking down into them during excavation work in the 1970s.
The rectory was once the site of Dimsdale House. When it was demolished and the brick building erected in Georgian times, expenses were reduced by using some of the stone, and building upwards from the basement. The stonework at the base of the rectory can still be seen.
The subterranean world of passageways and tunnels has always fascinated people, giving rise to tales of intrigue. During the Reformation, some of the old houses that we can visit today had priest holes, and we can recoil in horror at the small cold dark places where priests had to hide to escape persecution. Gervase Tindall, headmaster at the Grammar School, was a spy for Thomas Cromwell in the late 1530s.
During the Civil War many people had to hide from friends and neighbours, some who supported the King and some who supported Parliament. William Clarke, with whom Isaac Newton lodged while at school, was a vehement supporter of Parliament. He had public arguments with his neighbours in the street, and some of them were frightened by his outbursts. Some people were also arrested and questioned for passing letters in code.