The Spider Pass, near to Minas Morgul on the borders of Mordor.
Cirith Ungol was the route chosen by Frodo, on the advice of Gollum,
to enter Mordor. It was a high, narrow pass overlooked by a fortress
at the top. As an added safeguard, there lived Shelob, the greatest
of the giant spiders remaining in Middle-Earth. The route through
Cirith Ungol, included two very long stairways and a branching orc
tunnel where Shelob lived.