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Ogof Tan-y-Bryn is a prehistoric cave situated in Wales and carved into Dinantian limestone with subordinate sandstone and argillaceous rocks of Mississippian age. These strata, which underlie the site, form part of the extensive carboniferous geology characteristic of much of Wales and the British Isles. The cave's formation in this mixed sedimentary sequence reflects the dissolution patterns typical of limestone cave systems, where slightly acidic groundwater enlarged natural fractures over thousands of years to create underground chambers and passages.
The site has been recognised as a place of archaeological interest, yielding evidence of human activity during prehistoric periods when such caves served as shelter and refuge. Caves of this type often contain stratified deposits recording successive phases of occupation, from the Palaeolithic through to later periods. The limestone geology has aided preservation of organic remains and artefactual material that might otherwise be lost.
Ogof Tan-y-Bryn is protected by Cadw, Wales's historic monuments authority, under the reference CN204. This designation reflects its significance as a record of prehistoric settlement and land use in the Welsh landscape. The monument remains an important resource for understanding how early communities exploited natural rock shelters and adapted to their environment during the distant past.
Ogof Tan-y-Bryn is a scheduled monument protected by Cadw under reference CN204. View the official record →
Ogof Tan-y-Bryn is a prehistoric cave situated in Wales and carved into Dinantian limestone with subordinate sandstone and argillaceous rocks of Mississippian age. It is designated a Scheduled Ancient Monument by Cadw under reference CN204.
Ogof Tan-y-Bryn dates from the prehistoric period, and is classified as a cave. It is one of over 32,000 scheduled monuments protected across the UK.
Ogof Tan-y-Bryn is a Scheduled Ancient Monument, legally protected by Cadw — the body responsible for designating and safeguarding heritage sites in Wales. The official designation reference is CN204.
Several scheduled monuments lie within 10 km, including Hendre-Waelod Burial Chamber (6.9 km), Cefn Llechen cairns (8.7 km), Hut Groups N of Cerrig y Dinas (8.8 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of Ogof Tan-y-Bryn's history, each drawn from the record and mapped to the exact spot:
Every location is different. Not every section appears for every place, only what the historical record actually holds turns up in a report.
Ogof Tan-y-Bryn stands on Dinantian Rocks (Undifferentiated), bedrock that formed in the Mississippian. The rock here is limestone with subordinate sandstone and argillaceous rocks.