Tŷ Mawr in Holyhead,Wales. Is the site of around 50 stone hut ruins dating to around 500 BC. No one knows for sure who built the huts.
Many historians say they were the site of a big community that also farmed animals and traded.
The site was fully inspected in 1860. A number of items have been found there, such as Roman coins, bones, flint tools, and charcoal.
From my own personal experience, I have visited this place twice, and it was cold and windy both times. The harsh weather got me thinking about how the ancient people could survive here without modern technology.
There is not really much to see at the site as nature has overgrown many of the huts, but it is still worth a visit. Thankfully, there is a small parking lot just across the road, which I have recently added to Google Maps.
This is not the place you would want to be walking to in harsh weather, as it is quite far from the nearest town, so if you do plan to visit, my advice is to pack warm clothes and waterproofs and drive there.