Dotted across the landscape of Britain and Ireland, hillforts have been part of our story for millennia. Launched June 2017, for the first time a new online atlas captures all of their locations and key details in one resource.

With the help of citizen scientists from across England, Ireland, Northern Ireland, Scotland and Wales, a research team funded by the Arts and Humanities Research Council (AHRC) has spent the last five-years sifting and recording information on all the hillforts across Britain and Ireland. They have discovered there are 4,147 hillforts in total, and have collated details for every one on a website that will be accessible to the public – and completely free.

The team are drawn from the University of Edinburgh, University of Oxford, and University College Cork. Edinburgh’s Professor Ian Ralston, who co-led the project, said: “Standing on a windswept hillfort with dramatic views across the countryside, you really feel like you’re fully immersed in history. This research project is all about sharing the stories of the thousands of hillforts across Britain and Ireland in one place that is accessible to the public and researchers.”

This unique resource will provide free access to information about world-famous sites as well as many previously little-known hillforts, helping ramblers, cyclists, naturalists, and history enthusiasts discover them and their landscapes in all their variety. Project co-leader Professor Gary Lock at the University of Oxford said: “We hope it will encourage people to visit some incredible hillforts that they may never have known were right under their feet.”

Hilforts of Britain and Ireland. Scotland has 1694 hillforts. England has 1224 hillforts. Wales has 690 hillforts. Republic of Ireland has 475 hillforts. Northern Ireland has 32 hillforts. Isle of Man has 30 hillforts.

Mostly built during the Iron Age, the oldest hillforts date to around 1,000BC and the most recent to around 700AD. Hillforts were central to more than 1,500 years of ancient living: with numerous functions – some of which are yet to be fully uncovered – hillforts served as communal gathering spaces. The research also shows that, fascinatingly, not all hillforts are on hills; nor are they all forts.

Professor Alice Roberts of the University of Birmingham, presenter of Digging for Britain, and professor for Public Engagement with Science said “Hillforts are an astonishing reminder of the ancient past; monumental impressions left by our ancestors on the landscape. But some of them are more obvious, and more well-known than others. This new atlas draws on the latest research and maps over 4,000 hill forts – it makes this facet of our ancient heritage accessible to everybody.”

The online resource can be updated by the public via a wiki-style database. Through the citizen science initiative, around 100 members of the public collected data about the hillforts they visited, which was later analysed by the research team. They were asked to identify and record the characteristics of thousands of forts. The researchers wanted information not only about the upstanding, well-preserved forts but also sites where only cropmarks and remnants show where forts once stood. This process helped to develop the knowledge and skills of volunteers and enthusiasts.

Dr Martin Poulter, Wikimedian-in-residence for the Bodleian Library at the University of Oxford, said: “We have thousands of images from the public on the database. These freely reusable data and images will help to create content about hillforts on Wikipedia, and will direct readers to links for the main atlas website. The database also allows users to search for customised maps focused on a particular type of fort or region of the British Isles, whilst also combining hillfort locations with other data.”

The new data will be made available to the national monuments records of Britain and Ireland and will also help heritage managers, naturalists, archaeologists and policy makers to consider how we they look after the hillforts.

It is hoped that the atlas will help raise the profile of hillforts that are half-hidden and underappreciated in their local community. For example, crowned with a cluster of Beech trees, Chanctonbury Ring in West Sussex is a popular walking spot and plays host to Sussex’s premier Morris Dancing side; but few will realise that the stunning trail is an Iron Age hillfort with its own stories and ancient history. The online atlas will provide added interest to other established walking trails, too, such as the Chilterns Country Iron Age Fort Pub Walk, and the Swindon-based charitable Castles Bike Ride.

The project has also had significant public impact: for example it contributed to successful bids to the Heritage Lottery Fund by the Chilterns Area of Outstanding Natural Beauty Board.

The online atlas can be found at