Garden of Eden

Short definition from Wiktionary

Proper noun

1. 1
   In the Book of Genesis of the Bible and Surat Sad of the Qur'an, a garden at the source of the Gihon, Pishon, Tigris, and Euphrates rivers, where Adam and Eve first lived after being created.

Noun

1. 1
   An idyllic place wherein innocence and perfection reign; any delightful region or abode; a pastoral utopia; an Arcadia.
2. 2
   A state or condition of unsullied innocence.
3. 3
   A pattern that can only exist as an initial state and is not attainable from any other state.