(Salem, in Japanese original; Zalem, in French edition)
The midair city, an unachievable and mysterious metropolis, as the inhabitants of The Scrapyard have no access to it. It will be finally seen in Hyper Future Vision?, volume 7, Angel of Chaos.
As explained in Last Order, volume 10, Angel goes Nova, page 147, it was originally designed as a starship (or space shuttle) simulator. However, since generating antimatter that is fuel of the starship became the cause of the terraforming war, the starship and generating antimatter were sealed by the Ladder Treaty. Because of the historical details like the above, contacts with Tiphares which can arouse big countries’ suspicion were postponed.
Also, in Last Order, volume 10, Angel goes Nova, pages 177-181, we learn why there are eleven tubes connecting the midair city to the surface instead of ten or twelve, as it would be expected, after a dreadful aftershock that spread down the space elevator
adjective: Tipharean or Salemite
See also: Jerusalem and Nezher.
According to Wikipedia (edited):
Tiferet (Hebrew for adornment) or Tifereth, Tyfereth, Tiphereth - also known as Rakhamim (Hebrew for mercy,) or Shalom (Hebrew for peace) - is the sixth sefira in the Tree of Life in Kabbalah, which is the spirituality of Rabbinic Judaism. It has the common association of spirituality, balance, integration, beauty, miracles, compassion, and masculinity.