The Shield Generator for the Death Star is located deep inside an Imperial bunker in the dense foliage of Endor. A pivotal location in Star Wars Episode VI: Return of the Jedi, the whole fate of the Rebel Alliance plot to destroy the second Death Star and thwart Darth Sidious rests on the bunker being destroyed.
Related ThreadsShield Generator - last post by @ Jun 11, 2008
doom shield - last post by @ Feb 2, 2003
Space combat; large ships' shields - last post by @ Mar 3, 2012