Treryn Dinas is a headland near Treen, on the Penwith peninsula between Penberth Cove and Porthcurno in Cornwall, England.

The innermost rampart, up to 2 metres (6.6 ft) high, crosses the narrowest part of the headland.

The South West Coast Path runs alongside the outer rampart.

[1][2][3][4] On the promontory, Logan Rock is balanced on the rocky terrain about 30 metres (98 ft) above the sea.

[3] This rocky headland is the subject of an engraving of a painting by Thomas Allom entitled Treryn Castle in Fisher's Drawing Room Scrap Book (1833), together with a poetical illustration by Letitia Elizabeth Landon.