Ely Castle Mound

You can't miss the steep grassy mound that dominates Ely's skyline - it's what remains of the castle that once commanded this corner of Cambridgeshire. William the Conqueror's men raised it after 1066, and though the wooden fortress has long since rotted away, the earthwork itself is a proper statement of Norman power. Climb to the top and you get a view across the Fens that justifies the slight huffing and puffing.

It's a quick stop rather than a half-day attraction - twenty minutes up and around is plenty unless you're really into medieval fortifications. The mound sits just outside Ely town centre, so it works well as a leg-stretch between proper sightseeing at the Cathedral or wandering the high street. Kids will enjoy the scramble if they're the energetic type; older visitors might find the gradient a bit steep for what amounts to an empty field at the top.

Free to access, unsupervised - the sort of place you just turn up to. Best visited when it's not been raining, as the grass can get slippery. It's ideal if you're staying at Heatherbield Lodge or Hatters Meadows, both within easy reach, and gives you a sense of why the Normans bothered building here at all. The mound itself tells you everything you need to know about power and landscape - sometimes that's enough.