South Pembrokeshire
Pembroke Castle (Pembroke) - One reason to visit this great mighty Norman castle is to climb to the top of the Great Tower. The Great Tower (or Great Keep) dates back to 1204, and would have provided secure living quarters for the residents of the castle. Kids might even imagine they're Henry VII, born in this castle, and who later became the first Tudor king of England.
Pembroke Castle is a medieval biggie, with gatehouses, turrets, comfy garderobes (bathrooms), a Great Hall for entertaining, tons of passageways to explore and towers to climb. A diorama in the gatehouse shows William de Valence dining with his family.
Don't miss Wogan Cavern - spiral stone steps lead down to a huge space that was a once a water gate or storehouse.
In summer there are falconry and knights events at the castle.
Brass Rubbing Centre - Stop in the Brass Rubbing Centre near the entrance for kids to make their own medieval souvenir. (Open in the summer.)
Lower Common Park, south east of the castle, has a nice big
playground, with swings and climbing structures. This is a great place to picnic.
Carew Castle (Carew) - This is a smaller, beautifully preserved 14th century castle. Start your explorations of the castle by walking through the gatehouses, pass through the kitchen, into the Solar, where the lord and his family would gather. Cross over the inner ward to the Great Hall, decorated with coats of arms of the Tudors.
The Mill - Walk along the mill pond to the mill (there was a mill in the Middle Ages, but this one is somewhat later). Inside the mill, kids can see the mill stones and other mechanical stuff used in milling. Around are grassy areas, where you can picnic, as well as a picnic area with tables.
Go horseback riding - The Dunes Riding Centre (Narberth) has half hour rides for little kids, one hour and half day rides through green leafy woodlands.
Beaches - Tenby and Broad Haven all have flat, sandy beaches. Kids can play on the beach, making sand forts and castles, even if the weather isn't sunny. (We found the summer weather in Wales to be variable.)