What is near Trethomas: Caerphilly Castle first
There is no place to visit inside Trethomas’ built-up area; there are 4 within 5 km of its edge. One of them is cared for by Cadw. Beyond the town, National Museum Cardiff sits 12 km away.
Around Trethomas: where to begin
Then come 3 castles, behind Caerphilly Castle.
CastleRuperra Castle3.4 km outside town, to the southeastCastleCastleCastell Meredydd2.9 km outside town, to the east
CastleCraig Ruperra Motte3.4 km outside town, to the southeastEach has a page of its own: what it is, who runs it, the weather month by month and what else is near it.
The layout
Just outside town, most of the 4 sit to the southeast.
The dashed line is Trethomas’ built-up area; orange marks its middle (where most people live). Numbers match the list below. © OpenStreetMap contributors · ONS built-up area 2022
The list by type
Every one of them is among castles or historic places.
Green: inside Trethomas. Grey: within 5 km of its edge.
1 place is cared for by Cadw (Caerphilly Castle).
Every one of them
Here are the 4 places within 5 km of its edge.
Close and well known first. Churches and listed buildings are on the History page, not here.
Beyond the town
Start with National Museum Cardiff, 12 km off, the best known of 12.
MuseumNational Museum Cardiff12 km south · 373K visitors a year
CastleCardiff Castle12 km south
Castle · CadwCastell Coch8.8 km southwest
CathedralLlandaff Cathedral11 km south
Big drawMuseumSt Fagans Museum Visitor Centre14 km southwest · 610K visitors a year
CathedralCardiff Metropolitan Cathedral12 km south
CastleMorgraig Castle5.6 km southwest
CathedralNewport Cathedral12 km east
Castle · CadwNewport Castle12 km east
Abbey or priory · CadwTintern Abbey36 km east
Castle · CadwMonmouth Castle40 km northeast
Castle · CadwRaglan Castle29 km northeastPlaces well known beyond Trethomas (Wikipedia articles in several languages, published visitor counts, or a National Trust, English Heritage or Cadw property), close and famous first. Distances are straight lines from the middle of the town.
Your questions on Trethomas
What is there to see near Trethomas?
No attraction is mapped inside Trethomas itself. Within 5 km of it are Caerphilly Castle, Ruperra Castle, Castell Meredydd and Craig Ruperra Motte.
Does Trethomas have a museum?
No museum or gallery is mapped in or within 5 km of Trethomas.
Is there a National Trust or English Heritage property near Trethomas?
Yes. In or within 5 km of Trethomas, 1 place is cared for by Cadw (Caerphilly Castle).
What are the best-known days out near Trethomas?
Within 40 km: National Museum Cardiff (12 km), Cardiff Castle (12 km), Castell Coch (8.8 km), Llandaff Cathedral (11 km).
How is this list made?
From OpenStreetMap (museums, galleries, zoos, theme parks and attractions, castles, forts and abbeys, and historic houses and gardens that are open to visitors) and Wikidata (what each place is, who runs it, its website and visitor counts). A place counts for Trethomas when it is inside the ONS 2022 built-up area, and as nearby within 5 km of its edge. Opening times and prices are not shown: check the official site.
Places: OpenStreetMap (© OpenStreetMap contributors, Open Database Licence) and Wikidata (CC0), placed in the ONS 2022 built-up area (Open Government Licence v3.0). Visitor counts are the latest Wikidata gives, with their year.
Photos: each place’s Wikidata image, from Wikimedia Commons under the licence below (our copy, resized).
Photo credits (14)
- Ruperra Castle: Andrew King, CC BY-SA 2.0, Wikimedia Commons
- Craig Ruperra Motte: Jeremy Bolwell, CC BY-SA 2.0, Wikimedia Commons
- National Museum Cardiff: Ham II, CC BY-SA 3.0, Wikimedia Commons
- Cardiff Castle: Tevfik Teker, CC BY 3.0, Wikimedia Commons
- Castell Coch: Hchc2009, CC BY-SA 4.0, Wikimedia Commons
- Llandaff Cathedral: Bill Boaden, CC BY-SA 2.0, Wikimedia Commons
- St Fagans Museum Visitor Centre: Sionk, CC BY-SA 4.0, Wikimedia Commons
- Cardiff Metropolitan Cathedral: Ham II, CC BY-SA 4.0, Wikimedia Commons
- Morgraig Castle: John Lord, CC BY-SA 2.0, Wikimedia Commons
- Newport Cathedral: The original uploader was Owain at English Wikipedia., CC BY-SA 2.5, Wikimedia Commons
- Newport Castle: The original uploader was Owain at English Wikipedia., CC BY-SA 2.5, Wikimedia Commons
- Tintern Abbey: Saffron Blaze, CC BY-SA 3.0, Wikimedia Commons
- Monmouth Castle: Pauline Eccles, CC BY-SA 2.0, Wikimedia Commons
- Raglan Castle: Tyssil, CC BY-SA 3.0, Wikimedia Commons
Contains public sector information licensed under the Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right 2026. Contains OS data © Crown copyright and database right 2026 (ONS boundaries). Northern Ireland: Source: NISRA; contains Land & Property Services data and Ordnance Survey of Northern Ireland information, © Crown copyright, licensed under the Open Government Licence v3.0. Scotland: contains National Records of Scotland data, Registers of Scotland data and SEPA data, © Crown copyright / © SEPA 2025, licensed under the Open Government Licence v3.0.