A Tudor -Gothic style Victorian mansion house built by Christopher Rice Mansell Thomas in 1830. It was built on a site which had been occupied for around 4000 yrs and from the 11th century was a Cistercian Abbey. The monastic ruins can still be seen today. There is also an 18th century orangery completed in 1790 which is the largest in Britain.In addition a citrus house built circa 1800 has been restored and now houses a collection of citrus plants.During world war 11 both British and American troops were posted at Margam Castle. General Dwight Eisenhower visited shortly before D-Day to prepare the soldiers for war. Today, the castle is in the care of Neath Port Talbot Count Council and is a Grade 1 listed building.