Old maps at various scales can be obtained from specialist map-dealers, second-hand bookstores and elsewhere. Copies will often be found deposited in libraries or museums. A few specialist publishers offer ‘new’ versions of old maps.
‘Six inch’ and ’25 inch’ maps
Of particular interest to local historians and indeed anyone wanting to look at changes in the landscape over the past 150 years are the 1:10560 (6″-mile) scale and 1:2500 (25″-mile) scale sheets published by the Ordnance Survey. 6″-mile sheets covering the Powys, RCT and Merthyr Tydfil sections of the Geopark can be inspected at Brecon library and those for the Carmarthenshire section at the record office in Carmarthen.
A search on the web will reveal that both originals and facsimile copies of these sheets and others can be purchased from various sources.
You can also view many of the published historical six-inch scale (1:10,560) and twenty five inch scale (1:2500) Ordnance Survey maps of the Geopark area on-line for free at the National Library of Scotland’s website.