Canvas Print of The limestone cliffs at Llantwit Major beach on a winter afternoon. The low winter sun has lit up the yellow limestone and helped show good detail. Llantwit Major beach is on the Glamorgan Heritage Coast. It is also known as Colhuw, or Colhugh, Beach. Because of the fragility of the limestone cliffs along the Glamorgan Heritage Coast it is best not to walk under them. The Glamorgan Coast is all about limestone; carboniferous and Lias or Liassic limestone. There are also sandy beaches and coves with lots to explore.