The landscape of Anglesey is generally low and undulating, with a predominantly northeast to southwest line of drainage and the main watershed in the east. The highest point at 230m is Mynydd Twr near Holyhead.

Much of the centre of the island is covered in glacial till, with bedrock evident as occasional rocky knolls. These areas are predominantly agricultural. Indeed, only 14% of the island boasts any natural or semi-natural vegetation.

The coast, in contrast, exposes the underlying hard geology, often in spectacular cliffs such as Gogarth on Holy Island, and the intervening dunes and marshes. Most of the coast of Anglesey was designated an Area of Outstanding Natural Beauty (AONB) in 1967.