The underground is a series abandoned subway stations and pockets of the old city simply built over. The buildings comprising the Underground were the remnants of Cities that stood upon the grounds where New Babylon now rests. What remains are twisting passages, old streets that still have the street level business fronts, cavernous halls, and miles upon miles of pathways. Though largely unmapped by most, the Underground has a few areas that have not only become popular, but have become integral to the Mega Cities shadowy side.
A section of the Underground that nestles up against the foundations of the Sea Wall on the coast. In 2075 Pirates demolished a section of the foundation on the ocean floor that gave entry way into a large underground chamber that has numerous passageways from it. This are became known as Pirate's Cove. Roughly the size of four city blocks, it now acts as a dock for smugglers, pirates, and lawless raiders to enter New Babylon beneath the watchful gaze of Dock Master's and Customs Agents. From here, all manner of illegal goods are brought to the Golden Mile and The Mall.