Anglesey is a large island off the north coast of Wales. It is relatively flat and low, the highest point being Holyhead Mountain at 220m.

The island contains the remains of a large number of Neolithic burial mounds. Some contain decorated stones. There are stone-built Neolithic huts to be found in fairly large villages. Stone circles are rare but there are plenty of standing stones. Many villages contain stone circles that were build in the last hundred years to host Eisteddfodds.
The one significant Iron Age site is a hillfort that was attacked by the Romans. This perhaps was the site of a Roman lighthouse. There are quite a few defended Romano-British settlements. The nearest fort was on the mainland.
As a major part of Henry’s campaign in Wales he constructed many great castles. Beaumaris is on Anglesey and is hailed as the best example of a concentric castle.