Fortress of Solitude

The Fortress of Solitude is a fictional fortress appearing in American comic books published by DC Comics and is Superman's Kryptonian base. The first Fortress was a huge iceberg. A huge golden key that only Superman or Supergirl could lift was needed to open the door. Superman built it. The second Fortress was a huge crystalline building. It looked similar to a pile of crystals and icebergs. A green crystal built the second Fortress. The third version was similar to the second one, but was bigger and looked different in the inside. This version was created by the Crystal of Knowledge, a ring-like crystal.

 In other media 
The fortress of Solitude has been adapted to different forms of media, including movies, television series, and video games.

Category:Superman
Category:Fictional buildings and structures