similar to the objects found in the Batcave. It has various scientific facilities as well, including a time telescope that can receive brief cryptic messages with reception of limited quality from the future. Earth One In Superman: Earth One graphic novel series, the Fortress of Solitude was built by Superman's Krytonian ship's AI, using the Arctic's cave system. Other media Television Animation Super Friends The Fortress has several appearances in the Super Friends animated series. The Super Friends version of the Fortress of Solitude is said to be located "in a deserted region of the frozen Arctic". In the episode "Terror at 20,000 Fathoms", Superman gives Aquaman, the Wonder Twins and Gleek a guided tour of the Fortress showing off many structures such as the Bottle City of Kandor. In a 1980 episode titled "Journey into Blackness", which said the Fortress was located "in a frozen and desolate area of the North Pole", Superman spots a black hole headed towards Earth using a telescope in the Fortress. In a 1980 episode titled "Revenge of Bizarro", Superman goes his Fortress of Solitude to stop Bizarro and return the Bizarro Super Friends back to normal with an Anti-Bizarro ray. A 1981 episode titled "Evil From Krypton" depicted the Fortress with a somewhat crystalline exterior and without the giant key, reminiscent of its film appearances. In a 1986 episode titled "The Death of Superman", the Fortress more closely resembles the pre-Crisis comic-book version, including a giant yellow key whose use required the combined efforts of Green Lantern, Wonder Woman and Cyborg. DC animated universe Superman: The Animated Series and Justice League Unlimited present a slightly altered version, with the Fortress located in the ocean underneath the Arctic tundra; access was gained by diving into the Arctic water and emerging in an opening inside the Fortress. This version contained an alien zoo housing alien life-forms saved from the Preserver's ship and some computer equipment, along with a Brainiac information sphere stolen from his hijacked spacecraft just before it was destroyed, which is used by Superman to access information about Krypton. The fortress also contains massive sculptures of Superman's biological parents, Jor-El and Lara, serving as monuments to Krypton. The Fortress of Solitude is also a major setting for the Justice League Unlimited episode "For the Man Who Has Everything". A fight with the warlord Mongul took place there, after he delivered a parasite capable