34497a3fe0ef52949a1ba8e99894ed69 This article belongs to the Classic Continuity.

Undertown is a subterranean alien city under the Earth's surface. It is one of the major settings for Omniverse. Undertown is an underground alien settlement where many kinds of alien species live and thrive below Bellwood.



In The More Things Change: Part 2, Ben first discovered Undertown when he and Rook pursued Bubble Helmet, Fistina, and Liam underground after defeating them at Mr. Baumann's store. Ben discovered that Psyphon had been using Undertown as a base for his racketeering operations. Ben ended up fighting Psyphon, Bubble Helmet, Fistina, Liam, Thunderpig, and other unnamed henchmen of Psyphon while fighting Buglizard. After Ben fought off Buglizard, Psyphon and his followers were arrested by the Plumbers.

In Hot Stretch, Ben and Rook follow Ester to a deeper section in Undertown where the Kraaho made plans to make Earth hotter for them to survive and live in.

In Special Delivery, Ben made deliveries for Mr. Baumann to multiple citizens and businesses of Undertown in compensation for unintentionally destroying his property, in the process discovering a secret auction held by Psyphon, whose plans he foiled.

In The Frogs of War: Part 1, the town was revealed to humans for the first time as frightened Undertown citizens launched through the asphalt above and left Earth in search of another home.

In The Frogs of War: Part 2, the residents of Undertown return to fight off the Incurseans and work with the humans side-by-side, stating that they'll work on living together in Bellwood.

Known Locations

Of Predator part1 62

Another place of Undertown

Notable Inhabitants

Notable Visitors


Ben 10: Omniverse

Season 1

Season 2

Season 3

Season 4

Season 5

Season 6

Season 7

Season 8

Naming and Translations

Language Name Origin
Spanish (HA) Pueblo Bajo
Sub-barrio (Ben 10: Omniverse, since Cough It Up)
From bajo, under and pueblo, town.
From sub-, sub and barrio, neighborhood.
Spanish (Spain) Submundo From sub-, sub- and mundo, world.


  • According to Derrick J. Wyatt, Undertown was created after Way Big's fight against Evil Way Big in Destroy All Aliens destroyed a large section of Bellwood. Alien workers were brought in to rebuild the city and these workers built a small camp underneath Bellwood that grew to the size of a city over the course of a few years.[1]
  • As of A Jolt from the Past, Undertown is, at least partly, powered by a volunteer group of Megawhatts who were freed from imprisonment by Ben and Rook.
  • According to Derrick J. Wyatt, there are Ectonurites living in the lower levels of Undertown.[3]


Start a Discussion Discussions about Undertown