Tresilian Bay is a small cove of rocks and some low tide sand backed by a storm bank of pebbles, which is home to plenty of driftwood and japanese knotweed. The bay lies within the Glamorgan Heritage Coast - a 14 mile stretch of spectacular coastline which runs from Aberthaw to Ogmore-by-Sea. As with most of the Glamorgan coast, the cliffs are of Blue Lias - an unstable mix of limestone and shale. A large white house (Tresilian House) sits in the small valley behind the beach, and the stream of Nant Tresilian flows along the valley and onto the shore. Access to the shore is from the coastal path, which runs along the shingle bank at the back of the beach.
There are caves on both sides of the bay; Reynard's Cave is the largest and is on the west side. Also nearby are a few WW2 pill boxes, situated alongside the coastal path. The closest parking is either at St Donats or Llantwit Major. Dogs are allowed at all times.