Upnor Castle

A squat red-brick fortress rises from the Medway's eastern bank, its gun emplacements trained on water that once mattered far more than it does now. Upnor Castle was built in 1567 to guard against Dutch naval raids, and standing on its ramparts you understand why - the river narrows here, funnelling everything approaching the naval dockyards at Chatham straight into the castle's cannons.

It's not enormous, so you're looking at ninety minutes maximum to properly walk it. The walls are thick, the views across the water are decent, and there's genuine Tudor-era grit to the place rather than the polished tourist experience you get at grander castles. History enthusiasts will find the military engineering satisfying, particularly if you're interested in Tudor defences and how England actually protected itself when invasion felt imminent.

Families with younger kids might find it underwhelming after half an hour unless they're really into climbing staircases. Walkers heading from Aylesford will appreciate it as a riverside detour rather than a destination in itself. The surrounding Medway Valley has proper rambling potential, and if you're staying at Kits Coty Glamping just five miles away, it's easily combined with a morning walk along the towpath.

Access is straightforward from Aylesford - follow the A3016 towards the river. Worth a punt if you're in the area and don't mind paying a small fee for something unmissably historical rather than Instagram-famous.