The Dead Sea Scrolls are a critical part of Evangelion lore, and are in the possession of the SEELE organization which uses them as reference to manufacture humanity's artificial evolution. The scrolls seemingly fore-tell humanity's evolutionary dead-end, the coming of the Angels, the Second Impact, and the Third Impact.
In reality the Dead Sea Scrolls were excavated between 1947 and 1956 from the Qumran Caves on the northwest shore of the Dead Sea, a lake in Israel. They contained roughly 850 documents, including the Old Testament and other religious texts not found within the Bible. The scrolls are of great religious and historical significance, as they are the only such remaining documents dating before 100 A.D.
For years there were rumors that the Vatican was hiding some of its contents, but in 2001 the entire manuscript was finally published. The majority of the scrolls are now housed in Israel (eight manuscripts at the Shrine of the Book and all others at the Rockefeller Museum, Jerusalem). There are also some texts in Jordan and Europe.