Hospital of Saint John The Baptist

You'll find the remains of this 15th-century charity hospital tucked away in Windsor, a sobering reminder of medieval welfare long before the NHS. Built by Henry V to care for the poor and sick, it's now largely ruins - stone walls and arches that speak more through absence than presence. What survives gives you a real sense of scale: this wasn't a small operation, but a proper institution that served the community for centuries.

History buffs will get the most from a visit here. There's no flashy interpretation centre or queues, just the physical fabric of the building itself and whatever information plaques remain. You'll need to check locally for opening times and access, as details are thin on the ground - it's genuinely off-radar. The nearest proper town is Marlow, just a short drive away, which makes sense as a base if you're combining this with other Thames-side exploration.

If you're camping in the area - and there are several sites within a few miles, including Penn Meadow Farm and Shillingridge - this works as a quiet half-hour detour rather than a major attraction. Don't expect crowds or facilities. It's the sort of place that appeals to those who find real history in crumbling stonework more affecting than any museum display. Kids might find it a bit dull unless they're already interested in medieval life. Give it an hour at most, and go on a clear day when the light picks out the architecture properly.