The entire headland forms the Pentire Peninsula Site of Special Scientific Interest, designated for its geology and flora and fauna including nationally rare plants.

Important examples noted include slates from the Upper Devonian period, several invertebrate species, predatory birds and grey seals.

[3] Pentire Head is formed of pillow lavas,[4][5] while The Rumps consists of altered dolerite,[6] and naturally occurring Prehnite has also been found on the cliffs.

[11] Sources are not always consistent between the names of the two mines, but from the mid 19th Century the headland produced over 1000 tons of lead ore and 19,000 ounces (540 kg) of silver.

[15] Today the fort itself can be identified by the three ramparts crossing the narrower strip of land linking the Rumps headland to the main part of Pentire Head.