You may locate the Underground Arms by entering through the maintenance door of the Neon District Station that leads you through a rusty, dull and incandescently lit hallway. You may also randomly find Underground Arms by exploring the vast network of caves and sewers in the Beggar's Cove. Underground Arms is placed next to the Curtain Quarters / Slums.
Underground Arms, is a shop for defense where you may by Firearms and Melee weapons. This store is the top and favorite place for Syndicates to purchase their weaponry. Ghetto, but reliable firearms are key for building and protecting the notorious crime organizations that haunt this district.
Weapons you can buy: