It was in private ownership until the 20th century, when it was donated to the National Trust by Sir Thomas Acland, Colonel Wiggin and Allan Hughes; a stone cairn was erected at the summit to commemorate the event.

There are extensive views from the summit, from where the Bristol and English Channel coasts, the Brecon Beacons including Pen Y Fan, Bodmin Moor, Dartmoor, the Severn Bridges and Cleeve Hill 86 miles (138 km) away in Gloucestershire are visible.

[20] A circular funerary stone mound 850 metres (2,790 ft) north of Dunkery Bridge, which is a 1.5-mile (2.4 km) walk from the summit, dates from the Neolithic or Bronze Age.

[21][22] Sweetworthy, on Dunkery Hill's north-facing slope, is the site of two Iron Age hillforts or enclosures;[23][24] one has a single rampart and external ditch, enclosing 0.25 hectares (0.62 acres).

[31] In 1918 Sir Thomas Acland granted to the National Trust a 500-year lease of a large part of the Holnicote Estate, including Dunkery Hill.

Labour Party activist and Member of Parliament Margaret Bondfield asked in the House of Commons if the government was willing to have it designated an ancient monument, to preserve it for future generations.

She received the reply that although the government was agreeable to having the hill listed there were no funds available for its purchase;[33] the beacon and surrounding mounds were subsequently designated an ancient monument.

Ling and bell heather, gorse, sessile oak, ash, rowan, hazel, bracken, mosses, liverworts, lichens and ferns all grow on the hill or in surrounding woodland, as well as some unique whitebeam species.

Exmoor ponies, red deer, pied flycatchers, wood warblers, lesser spotted woodpeckers, redstarts, dippers, snipe, skylarks and kestrels are some of the fauna to be found on or around the hill and in nearby Horner Woods, home to 14 of the 16 UK bat species and including barbastelle and Bechstein's bats.