Isle of Anglesey: History
=== Prehistory ===
The history of the settlement of the local people of Anglesey starts in the Mesolithic period. Anglesey and Great Britain were uninhabitable until after the previous ice age. It was not until 12,000 years ago that the island of Great Britain became hospitable. The oldest excavated sites on Anglesey include Trwyn Du (Welsh: Black nose) at Aberffraw. The Mesolithic site located at Aberffraw Bay (Porth Terfyn) was buried underneath a Bronze Age 'kerb cairn' which was constructed c. 2000 BC. The bowl barrow (kerb cairn) covered a material deposited from the early Mesolithic period; the archeological find dates to 7000 BC. After millennia of hunter-gather civilisation in the British Isles, the first villages were constructed from 4000 BC. Neolithic settlements were built in the form of long houses, and one of the first villages in Wales was built at Llanfaethlu on Anglesey. Another example of a permanent settlement on Anglesey is the Bronze Age burial mound, Bryn Celli Ddu (English: Dark Grove Hill). The mound started as a henge enclosure around 3000 BC and was adapted several times over a millennium.
There are numerous megalithic monuments and menhirs in the county, testifying to the presence of humans in prehistory. Plas Newydd is near one of 28 cromlechs that remain on uplands overlooking the sea. The Welsh Triads claim that the island of Anglesey was once part of the mainland.
After the Neolithic age, the Bronze Age began (c. 2200 BC – 800 BC). Some sites were continually used for thousands of years from original henge enclosures, then during the Iron Age, and also some of these sites were later adapted by Celts into hillforts and finally were in use during the Roman period (c. 100 AD) as roundhouses. Castell Bryn Gwyn (English: White hill castle, also called Bryn Beddau, or the "hill of graves") near Llanidan, Anglesey is an example of a Neolithic site that became a hillfort that was used until the Roman period by the Ordovices, the local tribe who were defeated in battle by a Roman legion (c. 78 AD). Bronze Age monuments were also built throughout the British Isles. During this period, the Mynydd Bach cairn in South-west Anglesey was being used. It is a Beaker period prehistoric funerary monument.
During the Iron Age the Celts built dwellings huts, also known as roundhouses. These were established near the previous settlements. Some huts with walled enclosures were discovered on the banks of the river (Welsh: afon) Gwna near. An example of a well-preserved hut circle is over the Cymyran Strait on Holy Island. The Holyhead Mountain Hut Circles (Welsh: Tŷ Mawr / Cytiau'r Gwyddelod, Big house / "Irishmen's Huts") were inhabited by ancient Celts and were first occupied before the Iron Age, c. 1000 BC. The Anglesey Iron Age began after 500 BC. Archeological research discovered limpet shells which were found from 200 BC on a wall at Tŷ Mawr and Roman-era pottery from the 3rd to 4th centuries AD. Some of these huts were still being used for agricultural purposes as late as the 6th century. The first excavation of Ty Mawr was conducted by William Owen Stanley of Penrhos, Anglesey (son of Baron Stanley of Alderley). …