Wales
Wales, the land of Merlin (Myrddin Emrys in Welsh), had great castles, misty lakes and deep underground caverns and mines.
Regions
Tip: Wales has steam trains, originally built to carry ore or timber. These trains pass through some absolutely glorious scenery, some places you can't get to by car. Steam trains have appeal for kids (is it all that puffy white smoke) and this is the perfect thing for a day trip.
Fun food
At tea time, try Welsh Rarebit, essentially cheese on toast, or Bara Brith (Speckled Bread) with lots of honey. The "speckles" are dried fruit or dates.
Shopping
Celtic jewellry is fun, earrings, bracelets, rings and brooches. For the more industrially minded, bring back a real miner's lamp or other souvenirs from the coal, slate and gold mines.