The Government is to purchase the Great Blasket island - An Blascaod Mór - Minister for the Environment Dick Roche announced last night.
The deal involves buying out a number of landowners and will cost €1.7 million.
The Department of the Environment also set out details of a management plan for the island.
The plan will involve the development of a new pier, cafe and public facilities.
Houses remaining in private ownership on the island, outside of the core village area, may also be refurbished for residential use.
The last inhabitants on the island, off the Kerry coast, were evacuated in the early 1950s. The State has had plans to buy An Blascaod Mór for more than 15 years.
In 1989 former taoiseach Charles Haughey announced plans for the State to buy the 450- hectare island to develop it as an historic national park.
However, the legislation drafted to carry out the plan was ruled unconstitutional by the Supreme Court in 1999.
In 2002 the current Government decided in principle to open negotiations with landowners on the purchase of their property.
Mr Roche said last night that the purchase of An Blascaod Mór marked "the culmination of many years of effort on the part of the State to protect an important element of our national cultural, historic and linguistic heritage".
"The Government has now decided that we need to take forward the heads of agreement and the first step will be to complete the purchase of these land interests on the island over the next number of months," Mr Roche stated last night.
The island management plan sets out principles governing ownership, development and tourist access. A new pier will be built on An Blascaod Mór and the existing pier on the mainland at DúChaoin will be upgraded.
The core village on the island will be conserved and consolidated in its present ruined state.
The principal landowner will be allowed to develop a cafe with new public facilities. These will be the only new structures permitted.
The plan states that houses that remain in private ownership outside of the core village area may be refurbished for residential use. However, no new buildings will be allowed. Any refurbishment will also have to be in accordance with State requirements, planning legislation and local area plans.
"Existing grazing rights will be retained, as the natural habitat requires the continuation of some grazing", the plan states.
The State will control the stocking rate on the island. Initially there will also be restrictions on the number of paying visitors to the island, with no more than 400 allowed per day. The plan says that this move is to protect the fragile nature of the natural heritage and the ruins on the island.
