The BBC News website has a report about a new and comprehensive catalogue of hill forts in the British Isles. Researchers discovered 4,147 sites across the UK and Ireland, with nearly 40% of them being found in Scotland. The illustrated story can be seen here
The Oxford Times also has a report about this, with special reference to local examples as follows:
A new online atlas of Britain’s 4,100 hillforts has been developed by academics from Oxford, Edinburgh and University College Cork. Mostly built during the Iron Age, the oldest hillforts date to 1,000BC and the most recent to 700AD. Among the local forts mapped are Thornbury, just off the Botley Road at Binsey, and Ilbury Camp, halfway between Oxford and Banbury, which was mentioned in the Domesday Book.
The expandable map can be found online at hillforts.arch.ox.ac.uk.