Historic Wales: a first look at the new map portal for Welsh heritage

 

I spend most of my time peering at Wiltshire, at sarsens, long barrows and LiDAR hillshades, so it's good to look over the border now and then and see how our Welsh neighbours do things. The new Historic Wales portal is in public beta until 1 December 2026, and its team is asking for feedback. So I've had a good look round.

What it is and who's behind it

Historic Wales calls itself "the map enabled portal for historic environment information in Wales". It's run by the Royal Commission on the Ancient and Historical Monuments of Wales (RCAHMW) and built on Esri's ArcGIS Hub and Experience Builder. What makes it worth having is that it brings the main Welsh heritage datasets together in one map:

• Cadw (cadw.gov.wales): Scheduled Monuments (I counted 4,236 records), Listed Buildings, Registered Historic Parks & Gardens and Designated Wrecks.
• Heneb (heneb.org.uk), the new body that now runs the regional Historic Environment Records: the HER of Wales, a huge 271,366 points, each linking to its Archwilio record.
• RCAHMW: the National Monuments Record of Wales, split into terrestrial and maritime layers, with each point linking to Coflein.

Think of it as Wales's answer to England's Heritage Gateway and Historic England's National Heritage List map, but on one map. That's the bit I envy. In Wiltshire I have the scheduling on one site, the HER on another and the old maps on a third.

The historic maps are the real treat

The highlight for me is the "Historic Mapping" theme. RCAHMW is working with regional archives and the National Library of Wales to digitise and georeference historic maps, and the beta already includes:

• Enclosure maps, funded by the Welsh Government. Breconshire, Carmarthenshire, Denbighshire, Flintshire, Glamorgan, Monmouthshire, Montgomeryshire and Pembrokeshire are already in, with the rest promised. You can lay Brecon Forest in 1819 or Malltraeth Marsh in 1861 straight over today's map.
• Admiralty charts from the UK Hydrographic Office, covering Milford Haven in 1830, the Swellies in 1872, Holyhead harbour and dozens more. Together they make up a new Maritime map.
• 6-inch Ordnance Survey maps from 1868 to 1892, courtesy of the National Library of Scotland, plus a promise of the 25-inch first edition. Anglesey and Flintshire are said to be online already.
• Historic county and civil parish boundaries for 1860–89 and 1889–1906. They're really handy, because so many old records are filed by the pre-1974 counties.

One tip, because it caught me (and others) out: ticking "Historic Mapping" on its own shows nothing. Every map sheet starts switched off, so expand the group, then the county or chart set, and tick an individual sheet. Each one only covers its own patch, so zoom to it. Once you know that, it all works nicely. The 1880s 6-inch sheet around Pentre Ifan is crisp right down to field level.

There's a swipe tool for comparing old and new maps, a measure tool, a choice of basemaps, layer reordering and transparency, and a table view. Each historic county also has its own preset map.

Trying it on two old favourites

Naturally I went straight for Pentre Ifan and Bryn Celli Ddu. Both turn up in all three datasets:

• Pentre Ifan Chambered Tomb is scheduled as PE008, with a separate scheduling, PE504, for the standing stone 120 m SSW. It's also in the HER (Dyfed records such as DAT1471) and in Coflein as NPRN 101450.
• Bryn Celli Ddu is AN002 to Cadw, GAT2694 in the HER and NPRN 93827 in Coflein. Around it sit a plough-levelled cairn, a cup-marked outcrop and an enclosure to the south-west. That's exactly the sort of landscape context I like to see.

One catch. The map viewer has no place-name or site-name search box that I could find. You either pan and zoom, or open the attribute table and filter it. If you know where you're going that's fine. A casual visitor typing "Pentre Ifan" will expect more.

Open data: better than it looks

This is where the geek in me cheered. The data layers sit on public ArcGIS Feature Services, so anyone with a GIS, a QGIS install or a few lines of code can query them directly. The site also says the open datasets from RCAHMW and Cadw can be downloaded from the platform. The NMRW layer carries a clear "Crown copyright: RCAHMW" credit, and the splash screen notes that copyright stays with each contributing body, whose terms apply. Records come in both Welsh and English. Cadw names have a Welsh form ("Beddrod Siambr Bryn Celli Ddu"), and the NMRW has Welsh fields too. There's also a Cymraeg button on the map and a separate Welsh-language hub.

No LiDAR here, though

As a LiDAR obsessive (I built LiDAR Lens for Wiltshire), I looked hard for a hillshade layer and didn't find one in this beta. Wales has good open LiDAR, and a hillshade under the HER points, with a swipe against the enclosure maps, would be a wonderful combination.

On the phone

It works on a phone. The tools sit along the top and the layer list slides up from the bottom. It's a bit cramped, though, and on a narrow screen the Cymraeg button sits over the toolbar. You also have to tick a terms box on every visit before the map will let you in. Both are fair beta niggles.

Verdict

It's an excellent idea: three national datasets, a quarter of a million HER points and a growing library of georeferenced historic maps, all in one free viewer with open services underneath. Add a search box and some LiDAR, and England would have a real reason to be jealous. The beta runs until 1 December 2026 and the team really does want comments, so if you have a Welsh corner you love, give it a try and use the Feedback button on the home page.