‘Atlas of Hillforts’ Maps All 4,174 Hillforts In The UK And Ireland

"There are 4,174 hillforts dotted all over the British Isles and Ireland, making them one of the most prolific and well known legacies of the Iron Age. These whopping great constructions started to appear around 1,000 BC and remained in use until the Roman conquest. For the first time, each and every one of them has been united in an online atlas that lets you look up the one that’s nearest to you, and find out its basic details."

https://digventures.com/2017/06/atlas-of-hillforts-maps-every-single-one-of-britain-and-irelands-4174-hillforts/