If you want to hike up Pen y Fan 886m, the highest peak in South Wales, most people do it the easiest way from Pont ar Daf which is the high point of the Brecon to Merthyr road. This way is easy (in good weather) but is very crowded on weekends and school holidays. Either go early in the morning, or start your walk from one of the other paths eg Cwm Gwdi to the north, or Blaen y Glyn to the east, or one of the parking places in the Taf Fechan forest to the south.
You will see hidden gems off that the Amalfi Coast offers. You will have the opportunity to spend time on a private beach off the Amafi Coast. Have lunch where you can experience the local seafood. View the natural arch known as the "Lovers Arch". Many marriage proposals have occurred at this location.