Verulamium Park

The River Ver winds through 100 acres of proper woodland and open grassland just outside St Albans, and Verulamium Park is where you'll find the ruins of a Roman city alongside some genuinely peaceful walks. You get the sense that most visitors don't realise what they're looking at - those scattered stone foundations and the amphitheatre outlines are the remains of one of Roman Britain's largest towns, though honestly the park itself is the real draw rather than the historical bits.

Walkers will find this excellent. There are clear paths through the woods, open areas that catch the sun, and enough variety that you won't feel like you're trudging the same loop. The lake is proper pleasant, especially in spring when the water's calm and the light cuts through the trees nicely. You can easily spend two hours here without rushing, or knock it around in 45 minutes if you're just after fresh air.

Families with younger kids might find the historical interpretation a bit thin - there's not loads of signage explaining what you're looking at - but the open space itself keeps them entertained. Older children interested in Roman history will get more from it, though they'll probably want more detail than the park provides.

If you're basing yourself at Frogmore Park Homes or Cherry Green Trees nearby, this is absolutely worth the short drive. Free entry and no faffing about with visitor centre queues. Best visited outside school holidays when the paths aren't rammed.