The ACT section was transferred to the Commonwealth of Australia in 1915, as part of the Jervis Bay lands transferred by New South Wales to federal control to provide the national capital with access to the sea. While the bulk of this land was established as a separate Jervis Bay Territory when the Australian Capital Territory was granted self-government, the portion on the Beecroft Peninsula remains part of the ACT. The ACT portion of the peninsula consists of a strip of land around the southern edge of the peninsula, which is the northern headland of Jervis Bay. However, the Point Perpendicular lighthouse (and its grounds) at Point Perpendicular, which is the southern tip of the peninsula and at the northern entrance to Jervis Bay, remains an enclave of New South Wales territory within the ACT's enclave.
A large part of the peninsula (both NSW and ACT portions) is under the administration of the Royal Australian Navy for use as a live-firing range. For this reason, access to this part of the peninsula is restricted at certain times.
Due to strong winds and waves from the south the peninsula contains numerous caves and blowholes. Its varied fauna and vegetation have led to a request for the area to be made into a National Park. There is a town in the northeast of the peninsula called Currarong.
- Commonwealth law still requires that the national capital have access to the sea: See the Seat of Government Act 1908 , section 4.
- Although ACT lands on the Beecroft Peninsula are shown on official and other detailed maps of the area, it is not widely known that this area forms part of the ACT. This is probably because the area has no permanent residents, being reserved as a live firing range for the Royal Australian Navy. However, retention of this strip of coastline ensures ongoing compliance with the legal requirement, as set out in section 4 of the Seat of Government Act 1908, that the ACT "shall ... have access to the sea". The Point Perpendicular lighthouse, at the very tip of the Peninsula, is a small exclave of NSW territory cut off from the main part of NSW by the ACT land. A good online GIS map showing the Beecroft Peninsula, and those areas which are part of the ACT, can be found at the website of the Shire of Shoalhaven, the adjacent NSW municipality. This is the URL (NSW lands shown in yellow, ACT and JBT lands shown in pink): http://gis.shoalhaven.nsw.gov.au/maps/. The area of ACT land on the Beecroft Peninsula is clearly shown in the New South Wales Roads Directory (Map 177, grid ref. S 2), which is published by the National Roads and Motoring Association and is based on NSW Department of Lands maps. Several other maps showing the boundaries of the ACT exclave on the Beecroft Peninsula are available online, for example: http://www.exploroz.com/Places/24482/NSW/Longnose_Point.aspx