Village · 1,526 residents
Fair · among the lowest-scoring villages
Check Local Score out of 100 · 60 is typical for the country
Each arc is a topic, coloured by its score
Map outline: Official built-up area
Trethomas scores 50/100 overall, which the scorecard rates as fair — 60 is typical for the country.
It stands out for environment (81).
It scores lowest on health (24).
Scores come from official data on safety, schools, transport, prices, health, food & drink and the local environment, for Trethomas in Wales, each measured against the national average.
Trethomas is a hillside run of terraces above Caerphilly, the kind of place where the streets sit close together and the front doors open almost straight onto the pavement. It's compact and residential rather than a destination in itself — there's no obvious high street pull here, just rows of housing packed onto a steep valley grid, which explains a population density well above the Welsh average. It attracts people who want a foothold in the Caerphilly area without paying Cardiff prices, and the age profile — a median of 33, a decade younger than the Welsh norm — tells you this is a village of younger households rather than retirees.
Housing here is about as accessible as it gets: terraces dominate, freehold ownership is essentially universal, and a median price of £125,000 sits far below both the Welsh average and the wider Caerphilly county borough, where typical prices run closer to £191,000. A For Sale board on one of these streets is advertising an entry point, not a lifestyle upgrade — the trade-off being that incomes locally sit in the lowest decile nationally, and the area ranks in the second-most deprived decile in Wales, so affordability cuts both ways. For schooling, Graig-y-Rhacca Primary and Nursery serves the immediate community, and there's an independent option in Mynydd Haf School, though this is a one-primary village rather than a place with real choice. Transport is modest — seven stops locally rather than a rail-commuter setup — so this suits someone working locally or driving out rather than someone chasing an inter-city platform.
Green space is limited in scale — three pockets totalling under four hectares — but the environment grade still comes out strong, suggesting what's there is well-kept rather than extensive; this isn't a village built around park life so much as one where the surrounding valley landscape does the work. Health provision is more middling, and that's worth sitting with alongside the crime picture, which is the one figure that jars against everything else: safety here scores at the very top of the scale, yet the crime rate itself runs some three times higher than the Caerphilly county average, driven mostly by violence and anti-social behaviour rather than burglary or theft. That combination — a top safety grade sitting over a raw crime rate well above the surrounding borough — is the detail worth asking a local about before you commit, rather than a reason to walk away on its own.
This is a village for people prioritising a cheap freehold foothold and a tight-knit, younger community over amenity choice or transport links — you're trading polish and provision for a genuinely low cost of entry. It won't suit someone wanting rail commuting, extensive parkland, or a wide choice of schools, but for a first buyer or a family happy with one solid primary and a home of their own, it's a straightforward, unpretentious offer.
Data last updated: 19 October 2026
Pick another area to line them up side by side — the verdict, both Check Local Scores, and what actually separates them.