[2] The island is situated approximately 27 km (17 mi) from the South East Cape on a bearing of 149° and is contained within the Southwest National Park, part of the Tasmanian Wilderness World Heritage Site.

[3] Eddystone is known for its inaccessibility and distinctive shape, described by Abel Tasman in 1642 as "a tall, obtuse, square tower".

Seabirds recorded as nesting there include Australasian gannets, black-faced cormorants and fairy prions.

[6] Australian and New Zealand fur seals haul-out on the lower ledges when seas are not too rough.

[1] Together with the nearby Pedra Branca and Sidmouth Rock the island constitutes the 2 ha (4.9-acre) Pedra Branca Important Bird Area (IBA), identified as such by BirdLife International because it supports over 1% of the world populations of shy albatrosses and Australasian gannets.