Best castles to visit

[occa]

I'd like to take 12 and 15yo DC to visit a "proper" (medieval type) castle this summer. We're in Cambridge and I don't drive, so somewhere within easy-ish reach by train would be ideal.

Warwick looks amazing and you can camp in the grounds, which is very appealing, but it's a bit of a pita to get to (have to go into and across London then out again). Could anyone recommend any other good options?

TIA

South Wales is great for castles, most notably Caerphilly and Raglan. But it’s trickier without a car if you want to do more than Cardiff and Caerphilly.

Monmouthshire has a great variety of castles and less than an hour from Cardiff. Raglan, White Castle, Skenfrith, Abergavenny, Chepstow.

Cardiff has Cardiff Castle (a keep in the grounds and a more modern house which is a total contrast but just as interesting). Then just to the north (visible from the M4) is the folly of Castell Coch, which looks like a fairytale castle and though a folly it is fascinating. Caerphilly is the largest, most complete example of a concentric castle.