CADW Registered Historic Landscapes … Penmon
Penmon is the only Registered Historic Landscape on Anglesey. It covers is the headland which forms the southeastern corner of Anglesey. The land dips gently to the south and east from a scarp edge of steep slopes and cliffs along the north coast. Bwrdd Arthur, a prominent tabular hill, is the highest point on the scarp at 164m above sea level. Puffin Island (Priestholm or Ynys Seiriol) is a small island lying just off the tip.
Geology
This whole area is underlain by Carboniferous limestone with varying lithologies from massively bedded limestone to thinly bedded limestone alternating with shale or occasionally sandstone. Coarse gritstone – conglomerate beds are also common. Both major lithologies have been quarried extensively for building stone. Use the GeoMon geotrail leaflet for a self-guided walk around the headland at Penmon
History
Penmon is recognised as a registered historic landscape by CADW because it shows continuity of land use and occupation from the late prehistoric period through medieval to modern times. There are a number of important sites – but as part of the Bulkeley Estate it has not been developed or built over.
The Iron Age hillfort known as Bwrdd Arthur (Din Silwy), is one of the largest and the best preserved on Anglesey. It sits on a sloping bedding plane atop a thickly bedded limestone. The remaining slabs forming a perimeter wall are upturned clints from a limestone pavement [just as at Din lligwy). Its site reflects the strategic importance of the peninsula in controlling access to the Menai Strait.
There were towns at Llanfaes, and subsequently Beaumaris, during the medieval period, with evidence for successive Norman, Welsh and English attempts to control the area. In more recent times, limestone and “marble” quarrying has significantly altered parts of the coastline in the north.