Entry requires a special pair of underpants and the ability to pick Voxguard Platinums; the majority of players never set foot in the real Radome. Details are hazy and spoilery, but everyone knows that a bunch of gun-wielding Mormons from the city-state of Deseret occupy this place. Apparently, they're territorial and quick to spot a non-believer, leading them to lock the place down and seal up the secrets within, necessitating stealth for intruders. Beyond that, the Radome is swarthed in secrecy. Weyland-Utani is rumored to have a curious corporate interest in the place...
The Radome is largly forgotten, but if you can get inside, it is absolutely worth visiting. The experience of the dungeon itself is unique in HellMOO, using mechanics that aren't seen anywhere else in the game, as well as some unusual gameplay features. Even more remarkably, the quest that involves the Radome is not broken, and still rewards XP!
However, the zone was coded with a lack of foresight, and is showing its age. For this reason, if your character is above a certain power level, you may find navigating the Radome much easier than was originally intended, and some of the challenging aspects will be broken. Also note that to fully utilize the mechanics intended for use in the Radome, you must have your preference set to 1; you'll miss critical information in several areas if it is set to 0.