Further information can be found at https://www.prisonhistory.org/lockup/watchet-court-leet-lock-up/
'MARKET STREET 1. 5366 The Market House ST 0743 2/11 12.6.50 II GV 2. 182O, rebuilding of earlier Market House which stood in the centre of Market Street and was demolished in 1805. Repaired and ground floor converted to a museum in 1979. ... Small 'lock-up' under stairs. '
Historic England, National Heritage List for England, 'The Market House, Watchet', LEN 1180325 (https://historicengland.org.uk/listing/the-list/list-entry/1180325)
Historic England, National Heritage List for England, 'The Market House, Watchet', LEN 1180325 https://historicengland.org.uk/listing/the-list/list-entry/1180325
Roy's Blog, 'SOMERSET. Lock-ups at Milbourne Port, Somerton and Watchett.' (13 July 2013) http://roys-roy.blogspot.com/2013/07/somerset-lock-ups-at-somerton-and.html