"The undercity, you say? Just going to crawl down there and find your fortune are you? Simple as that, hey? And which entrance will you be using, pray tell? Have you talked some smugglers into letting you wander around on their turf until you find something you like? Are you going to try heading in by sea through the caves in Empire Hill when all the Khephale's archers are taking a piss? Better yet, maybe you can hold your breath long enough to use the underwater caves below the harbor. Can't swim, huh? On a long enough timetable, I'm sure you could clear out all the rock that seals off the old troll cave entrance in the side of Vargo's Hill, assuming Ilka the Faceless doesn't mind you pawing around below her castle, that is. Or maybe you just take a big gulp of fresh air and wander the sewers like a gong farmer until you find one of those older tunnels they say they found when they were digging them?
And assuming you find one of those old tunnels or voids, what then? Wander around until you get lost and starve, fall into a pit, or get eaten by The Queen of Eyes? All in hopes that you'll find some undiscovered treasure that nobody's stumbled across yet in over 1,000 years of idjits crawling around down there? You might as well just try to break into old Whore Tit's treasure vault. You'll die a lot faster, and they'll probably hang you from the Governor's Gate for a few days so we don't have to wonder what happened to you."--Captain Pap Janos, Stalwart Swords Mercenary Company
- Natural caves and caverns: Vargo the Trollslayer discovered Tir Vagyon when he noticed that part of an ancient structure formed the back wall of the troll cave he'd raided during a hunt. Other cave entrances can be found throughout the city. Most lead to reasonably shallow caves or systems, but a few intersect with what appear to be man-made structures and others have difficult-to-navigate passages that might go farther than most care to explore. Of particular interest are the sea caves in the side of Empire Hill, which many believe connect to the palace via escape tunnels constructed to allow the Khephale to escape the city by sea if his compound ever comes under serious attack.
- Tir Vagyon: The only known entrance to the ancient city whose looting led to the founding of Khezvaros has been sealed for a thousand years after the Trollslayer descendants decided that all accessible parts of the city had been explored. Of course, there are rumors of other entrances to Vargo's City of Fortune and unexplored sections of the city still waiting to be discovered. There are also rumors that something more sinister than a played out mine caused the Trollslayers to seal the cave.
- Smugglers' Tunnels: Over the centuries, smugglers have expanded and linked up natural caverns and older man-made tunnels to create a large network of underground tunnels that allow them to reach most parts of the city between the Oregvez and Ozpatak Rivers. These are among the most well-used and populated sections of the undercity, and are the setting of frequent altercations between different criminal organizations.
- The City Sewers: Not the most glamorous part of the undercity, but many of the other sections of the undercity were initially discovered when the sewers were being dug, so it may be the most direct route for some locales. Some of these old tunnels were incorporated into the sewer system, others were partially or completely sealed.
- The Carrion Moors: Although The Lord of Bones' realm is generally understood to be another plane of existence, it is reachable through tunnels accessible through The Pit, which has led to it commonly being thought of as existing below the city.
- Eloszorian Crypts: Based on reports, most historians believe these were small family crypts below wealthy estates that were on the outskirts of the city of Tir Vagyon.
- An ancient mine: Deep below the city there is a network of tunnels that appear to have been a mine during Eloszorian times.
- Temples and shrines to dark deities (both ancient and active), secret meeting places of cults and criminals of every stripe, underground fighting arenas, secret laboratories where horrific magical experiments are carried out, hidden cities full of inhuman creatures, legendary locales like Tolva's tomb, Kreeshka's pleasure pits, and the Vault of the Whisperers, and just about anything else one can imagine.