Thunderfield Castle (Site of)

All that's left of Thunderfield Castle is earthworks and a few lumps of masonry scattered across a field near Crawley. Not exactly Instagram material, but if you're into medieval archaeology or just fancy a bit of detective work with your OS map, it's worth the detour.

The castle was built in the 12th century and would have been a proper stronghold back in the day - a motte and bailey design typical of Norman settlement. Walking the site, you can still make out the raised mound where the main keep stood, and the ditches that once gave defenders a fighting chance against attackers. It's less "storming the ramparts" and more "trying to work out what went where," which some people find fascinating and others find a bit dull.

The real appeal here is for history enthusiasts or families with kids interested in archaeology. It's free to access and takes about 45 minutes to an hour if you're properly poking around. Go early morning or late afternoon when the light's better and the fields aren't full of weekend walkers.

If you're based at one of the caravan parks near Crawley - the Gatwick Caravan and Motorhome Club Campsite or Long Acres - Thunderfield makes a decent morning outing before heading somewhere with more visible remains. Pair it with a proper castle elsewhere in Surrey if you want something your family will actually queue to see.