2026-09-27T18:00:10+01:00https://marinefinds.org.uk/datalabs/terminology/object/format/jsonhttps://marinefinds.org.uk/datalabs/terminology/object/format/xmlhttps://marinefinds.org.uk/datalabs/terminology/object11410160452FUNDAMENTAL BENCH MARKYUsed by Ordnance Survey to record high accuracy height above Ordnance Datum Newlyn. Marked by a low concrete pillar, and maybe surrounded by railings, they comprise an underground chamber protecting the reference point, built directly onto stable bedrock.1P