Caerphilly Castle (Caerphilly) - Caerphilly is a cheese, but this one very big castle, 30 acres, and military architecture meant to impress. Roman soldiers were the first to spot this advantageous location, then the Normans, and in the 13th century an Anglo-Norman baron really beefed up the castle to keep out those rebellious Welsh. And it was a mighty fortress, with outer and inner moats, making the usual siege techniques impossible. Don't miss the model of the castle.

Rhondda Heritage Park (near Pontypridd) - Rhondda was once one of the big coal mines, where the search for "Black Gold" was big business. Go for a tour underground to find out about the life of a coal miner, check out the mining museum and multimedia exhibition, and children's play area.