Maiden Castle in Dorset, from the Environment Agency’s 1 m LiDAR terrain data. We shaded it so the banks and ditches stand out.

The Iron Age builders reworked the ramparts several times. They finished with three banks and two ditches round the hilltop, and one more of each on the gentler southern slope. In the second half of the 3rd century BC they took the defences round the whole hill and enclosed about 20 hectares.

The long, low mound near the middle of the hilltop is thousands of years older than the fort. It’s a Neolithic bank barrow from around 3500 BC, 546 m long and 17.5 m wide.

English Heritage looks after the site, and you can visit free at any reasonable time in daylight. It’s a Scheduled Monument, so look all you like, but please don’t detect or dig.

Sources: Historic England list entry 1015775, and English Heritage’s Maiden Castle page.

LiDAR © Environment Agency 2022, OGL v3.0. Full disclosure: we’re Shadowmark Maps, a small UK company building a LiDAR map app, and we made the image.