St Fagans National Museum of History is an open-air museum in Cardiff that displays structures from all over Wales. You can marvel at the beautifully painted walls of St Teilo’s Church (honoring the patron saint of apple trees), tour Welsh houses from various eras (having a bathtub in the kitchen is not uncommon), or try delicacies like Welsh cakes (not overly sweet). There is even a working farm where you can witness happy pigs devouring acorns (happy, that is, until they start fighting because one decides to eat the other’s acorns).
My time in southern Wales was really enjoyable in spite of the unpredictable weather (hostels had drying rooms for a reason). Spending a few days in Cardiff allows you to see the pigs of St Fagans, the dinosaurs in the Welsh National Museum (Wales, with its once-tropical climate, was full of them) and the fun, but then again slightly creepy, glass-eyed animal sculptures of the “Animal Wall” of Cardiff Castle among a host of other things.
There are plenty of activities to enjoy outside of Cardiff as well. I absolutely loved making a daytrip to Blaenavon for some more industrial tourism. The old Blaenavon Ironworks, with its huge balancing tower (emptying and filling water tanks would lift and lower mine carts), was a quiet place to explore while the tour of the mine at the Big Pit National Mining Museum was led by jovial, and very funny, former miner. Going down the mining elevator, wearing real safety equipemnt, and seeing the stalls where mine ponies were once kept for 50 weeks of the year really brought alive the sorts of challenges and conditions that workers faced underground.
If you aren’t keen on seeing the sorts of places that allowed us to live in a modern society today (not that I’m judging…), Brecon Beacons National Park is a wonderful place to hike. I remember being amazed as I walked through a glacier-carved path at how beautiful the scenery was. I thoroughly enjoyed my hike, just as I was thoroughly soaked by a rainstorm that started only once I reached the top of a ridge. I heartily recommend the YHA Brecon Beacons as an affordable and comfortable place to stay inside the park. Sitting by a warm fire after a cool day of hiking in the green hills is a true pleasure.