Desert City Underground
Desert City Underground aka El Farid Underground is the dungeon for which El Farid has practically all of its significance for. Prior to the release of NC 2.2, it was perhaps the most popular levelling spot for intermediate PSI Monks.
The mobs here primarily do poison damage, but also fire damage, so bring according equipment.
The dungeon has two levels. First level is a series of rooms, with one side room with a hackable supply box. Some rooms have higher spawn rates than others; generally those with sleeping bags and sacks lying around have a lower spawn rate, but generally no room is entirely safe. When going down into the second level, be prepared to appear amidst a group of scorpions; you can escape by running outside the room and around two corners to the left or to the right and find some cover there. If you have good condition, you can also find a way to jump up onto the roof.
On the second level of the El Farid dungeon is the Black Scorpion Queen, a 120/120 mob that is the boss of the zone. She spawns several other levels of scorpions who in turn spawn scorpions themselves. She is a popular levelling tool for any character with AoE, but especially for droners.
In her loot table are the occasional rare part, high level psi modules of average quality, and Titanium Vest that is popular with Private Eyes and GenTanks.