Playing around with @CITiZAN1's online mapping (https://citizan.org.uk/interactive-coastal-map/#zoom=11&lat=7277109.13912&lon=-87013.42023&layers=0B0000TF …) and finally figured out what these curious rectangular features w/ sockets cut into the rock at Staithes, N.Yorkshire—apparently they're 'fish garths/tanks' for crabs or shellfish https://citizan.org.uk/interactive-coastal-map/35896/ … :)pic.twitter.com/TbVwPYCYZH