The most influential family in the expansion of Porthcawl was probably the Brogden family from Sale, Manchester. John Brogden and his sons specialised in railway construction, iron-ore mining and coal mining. Their company bought a major share in Tondu ironworks and mined coal in the Ogmore valley. The Brogdens were instrumental in linking Porthcawl to the iron and coal mining industries of the valleys by rail.
Adjacent to Porthcawl are two older settlements, the village of Nottage and the village of Newton, but with the expansion of Porthcawl over the years these have become absorbed into the town. Newton has a 12th century Norman Church.
To the northern end of Porthcawl is Kenfig Nature Reserve, which is one the most important sites in Britain for nature conservation. It is a site of special interest and has many thousands of species of animal and plant life, including the rare Fen Orchid.
It was after the First World War that Porthcawl expanded as a popular seaside resort. In 1932 the Grand Pavilion Theatre was built. Part of the harbour was enclosed to create an area known as Salt Lake. This was very popular with swimmers, and small boats were also available for hire.
Porthcawl has many sandy beaches and to the southern end of Porthcawl is the Glamorgan Heritage Coast, which is also to become a site of special scientific interest.