Essex is a much-fortified county. Its coast is littered with coastal fortifications from all periods from Roman times to World War 2. Inland, it has its share of medieval castles. But Iron Age hill forts are not something we expect in our county, not least because of the relative shortage of prominent hills.

Certainly there is nothing like the magnificent Maiden Castle in Dorset, but several locations do contain the remains of forts that date back to our oldest tribes in the pre-Roman period: the Trinovantes and the Catuvellauni.

While both tribes had territory crossing several modern counties, they both had a share in Essex, and some argue that a number of hill forts were built along a line of disputed territories. These include Ambresbury Banks in Epping Forest, Loughton Camp, Ring Hill Camp at Littlebury and Caley Wood, Little Hadham (just over the border in Hertfordshire).

The remains at Ambresbury and Loughton are substantial enough to be easily visible. Ambresbury Banks encloses eleven acres of land with a ditch and a single bank which is still six feet high. One of the six current breaks in the circuit is probably an original entrance, and has rough stone blocks reinforcing the exposed ends of the bank.

Having been excavated nine times we have some evidence through pottery and arrowheads of its age: it is estimated to have been built about 700 BC and abandoned 42 AD – the year the Romans came.

While visitors can clearly see the bank and ditch, the extensive tree cover is misleading – none of this would have been present originally.

Also in Epping Forest, near Loughton, is Loughton Camp. This covers ten acres and has a low bank and ditch still visible. It's believed that this was once much more substantial, and its position on a ridge of high ground would give it some strategic significance.

Both sites are Scheduled Ancient Earthworks and thus protected. A tantalising (but almost certainly untrue) legend associated with both is that Boudica made her last stand against the Romans here – but there are plenty of alternative and more plausible sites for this.