souterrain

Underground passages carved into the rock don't usually make for exciting days out, but this souterrain near Newcastle is genuinely worth digging into. It's essentially an Iron Age tunnel system - probably used for storage or refuge - and you can actually walk through sections of it, which beats reading about archaeology in a museum.

The passage is narrow and atmospheric in places, low enough that taller visitors will be ducking. It's dark down there, so a torch is essential, and the whole thing feels properly ancient rather than over-packaged for tourism. You're looking at maybe thirty minutes to an hour depending on how carefully you explore.

Families with older kids will get more from it than the under-eights, who might find it a bit claustrophobic or boring. Walkers combining it with a trip to the Mourne Mountains nearby will find it a decent add-on, though not a reason to plan your whole trip around. If you're staying at Edgewater Holiday Park, it's only five or so miles away and makes sense as a rainy-day stop.

The location near Newcastle means you're well-positioned for the coastal scenery that area offers. Ring ahead before you go - opening hours aren't always clear, and access can be restricted after heavy rain when the passages flood. Free entry, which helps offset the drive if you're not entirely convinced.