The Diamond Cave is a cave in the Dornish Marches.
During the reign of Aerys II Targaryen, a band of outlaws known as the Bandit Lords kidnapped Lord and Lady Dondarrion and held them in the Diamond Cave. Ser Arthur Dayne then slaughtered the outlaws and rescued the Dondarrions.
In the books
In the A Song of Ice and Fire novels, this cave is not mentioned.