Top 9 Natural Monuments around Pentraeth

On the longest day of the year, sunlight flows into the passageway of this Neolithic burial grounds. Bryn Celli Ddu Burial Chamber is one of Anglesey’s most famous prehistoric landmarks, Bryn Celli Ddu (the ‘Mound in the Dark Grove’ in English) is actually two sites in one. In the early Neolithic (New Stone Age) period, a henge (bank and ditch) enclosing a circle of stones was built here, to be replaced later by a chambered tomb beneath a mound measuring up to 85ft/26m in diameter. Inside, a long, narrow passage leads to an octagonal chamber 8 feet/2.4m across, where artefacts such as human bones, arrowheads, and carved stones have been found.

Large sandy bay surrounded by dunes. On the north side there are large, striking limestone cliffs of Castell Mawr - certainly geologically interesting, looks like climbers could have fun here... The beach itself is a really large (!) sandy bay, very popular in summer but largely deserted out of season. You can sometimes see kitesurfers and windsurfers here. There is parking behind the dunes and there is a small beach café and shop.

A small but tough and technical climb, beware of sharp rocks on the left hand side when descending

The Dingle Local Nature Reserve is a 10 hectare (25 acre) wooded valley rich in wildlife and history. It is bisected by the river Cefni, which comes from the Welsh word "cafn" meaning trough or hollow. The Dingle is a steep sided gorge formed by glacial meltwater during the last ice age hence one of its Welsh names Nant y Dilyw - Valley of the Deluge. Another name for the Dingle is Nant y Pandy - Brook of the Fulling Mill. This refers to the old wool processing plant situated upstream. Much of the reserve is ancient woodland which led to it being known as the Dingle as early as the 1830s. Dingle literally means steep wooded valley.

This huge, abrupt limestone rock is an extraordinary feature on Anglesey's north eastern coast. With sheer sides and a top covered in vegetation, it's thought to have once been the site of an Iron Age hillfort. Today, you can walk around its base and listen to the cries of the birds that nest in its crevices.

Mynydd Bodafon is a small collection of peaks including the Arwydd which is the highest point on the island of Anglesey. It lies about 2½ miles west of the coastal town of Moelfre and ⅔ of a mile south-west of the hamlet of Brynrefail. The meaning of Bodafon is obscure. It is a UK listed Marilyn.

Remember that scene in Raiders of the Lost Ark where Indiana Jones directs a beam of light through a chamber to show the location of the ark? This is where that happens for real. This prehistoric burial chamber was also used to chart the turn of the seasons, and around the time of the summer solstice (longest day), sunlight is funnelled through the front door into a single beam, illuminating the mysterious standing stone at the heart of the chamber.

Bryn Celli Ddu (‘Mound in the Dark’) is one of Anglesey’s most famous prehistoric landmarks. The great thing is, you can actually walk inside and through this neolithic burial chamber. However, to see Bryn Celli Ddu’s most striking feature, you have to be there on the summer solstice. As the sun rises, light shines directly down the tomb’s passageway to illuminate the chamber within.