Ye Ole Survey Monuments
This map showcases all the Bolt type of trig points found in the UK that we've successfully imported into our database.
Locations which are not marked with an 
icon may be available to place a new cache if you wish! Just head on over to our New Request form to get started.
A bolt trig point is a small, brass or metal bolt set into rock, concrete, or masonry. It serves as a survey marker for accurate mapping, often used in places where a full trig pillar isn’t practical.
Important to note: the locations displayed for "Ye Ole Survey Monument Caches" represent the trig point itself, not the hidden geocache.
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YOSM Locations | | |  |
Pillar | | |  |
Bolt | | |  |
Rivet | | |  |
Cannon | | |  |
Surface Block | | |  |
Intersected Station |
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Buried Block | | |  |
FBM | | |  |
Disc | | |  |
Cut | | |  |
Berntsen | | |  |
Concrete Ring | | |  |
Active Station |
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Brass Plate | | |  |
Block | | |  |
Pipe | | |  |
Spider | | |  |
Fenomark | | |  |
Curry Stool | | |  |
Platform Bolt |
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Unknown/Other | | | All Trig Points | | | |||||||||||||||
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Archived | These maps were last updated on 21 February 2025 | |||||||||||||||||