If museums are on your list, you might want to check out the upcoming exhibitions at The Royal Mint Experience in Llantrisant. It's also full of great shops and restaurants, so you can spend the afternoon having a wander. If you want to experience more of the culture Pontyclun has to offer, head to Llantrisant Castle and Dyffryn Gardens and Arboretum.
After visiting Newcastle Castle, make a plan to see the other sights and activities in Coity Higher. Discover the area's spas and seek out its golf courses.