{"entry-date":"2026-06-11","start-date":"1979-10-08","end-date":"","entity":13903929,"name":"Part of the mining complex of Wheal Basset and Grylls Mine called Tyack's Shaft","dataset":"scheduled-monument","typology":"geography","reference":"1007289","prefix":"scheduled-monument","organisation-entity":16,"geometry":"MULTIPOLYGON (((-5.230182 50.15103, -5.230263 50.151155, -5.230411 50.151116, -5.230334 50.15099, -5.230182 50.15103)))","point":"POINT (-5.230297 50.151072)","quality":"authoritative","documentation-url":"https://historicengland.org.uk/listing/the-list/list-entry/1007289"}