A location!

It turns out that Mt. Nemrut might be the best location. It is a popular toursit attraction built to honor the goodness of a king and his special relationship with the gods. It has lots of broken statues. It's 7,000 feet in altitude. It doesn't require special permission to get into and is fairly isolated from the war zones. It would be easy to have symbols hidden among the ruins that would guide them to the secret entrance to the library which would be underground where the king is buried. In fact, the origin of the marks might be in the site. I've already verified Star, Crescent, and Pyramid. A deep earthquake caused by the sound generator that breaks all the glass would entomb the library and anyone in it permanently.

Nemrut Dag (Mt Nemrud) is a mountain measuring 2,150meters in height. It is located near the village of Karadut in Kahta county in the province of Adiyaman. Kings of the Kommagene dynasty from 80 B.C. to 72 A.D ruled Adiyaman and its vicinity. This kingdom, whose capital was Samosata (now called Samsat), was founded around 80 B.C. by Mithridates 1, father of Antiochos 1.

The kingdom's independence came to an end with its defeat by Roman legions in the last of the Kommagene wars and it became part of the Roman province of Syria. At its height, Kommagene extended from the Toros (Taurus) mountains on the north to the Firat (Euphrates) river on the east and southeast, to present-day Gaziantep on the south, and to the county of Pazarcik in Kahramanmaras on the west. The magnificent ruins on the summit of Mt Nemrud are not those of an inhabited site however. They are instead the famous tumulus (burial mound) and hierotheseion (a word that is derived from Greek and refers to the sacred burial precinct of the royal family, and whose use is known only in Kommagene) of King Antiochos I of Kommagene, who ruled from 69 to 36 B.C.

In a cult inscription, King Antiochos declares that he had the site built for the ages and generations that were to follow him "as a debt of thanks to the gods and to his deified ancestors for their manifest assistance". The king also declares that his aim was to provide for the people an "example of the piety that the gods commanded be shown towards the gods and towards ancestors.

"Professor K. Dorner has traced the genealogy of Antiochos 1, who was himself born of a Persian father and a Seleucid-Macedonian mother. His findings indicate that Antiochos I of Commagene claimed descent, through his father Mithridates, from Dareios (Darius) 1 (522-486 B.C.) and, through his mother Laodike, from Alexander the Great (356-323 B.C.)

Mt Nemrud is located 100 kms from Adiyaman. No reference is made to it in ancient sources. Karl Sester, a German road engineer, rediscovered it in modern times in 1881. An expedition to Mt Nemrud was organized in 1882-83 by Karl Humann and Otto Puchstein, who published their findings in a book entitled Reisen in Kleinasien und Nordsyrien (Berlin 1890). Osman Hamdi Bey and Osgan Effendi also investigated the site in 1883 and their findings were published in a book entitled Le Tumulus de Nemroud Dagh (Istanbul 1883). F. Karl Dorner and Rudolf Naumann mounted an expedition to Mt Nemrud in 1938. Dorner returned to the site after 1951 and began working there with the US researcher Teresa Goell.

In 1984, a Turkish-German team led by Professor Dorner successfully carried out restoration work at the site. Excavation and restoration work has been continuing since 1989 under the direction of Sencer Sahin. In 1989, Nemrut Dag and its environs were declared a national park. The tumulus on the summit of Mt Nemrud measures 50 meters high and covers an area 150 meters in diameter. It is formed from stones the size of a fist and is bounded on the east, west, and north by terraced courts carved out of the native rock. The eastern court was the center of the sacred precinct and is the most important group of sculptural and architectural works. It is surrounded on the west by colossal statues, on the east by a fire altar in the shape of a stepped pyramid, and on the north and south by low walls of orthostats (upright stone slabs) standing on a long, narrow base.

http://www.adiyamanli.org/mt_nemrut.htm.