Bellwood

Bellwood is the hometown of the Tennyson family, and the main setting for Alien Force, Ultimate Alien and Omniverse.

Various members of the Plumbers also live in this town.

The Plumber base that stores the Hands of Armageddon is below this town.

Their newspaper is The Bellwood Bugle.

The main elementary school of the town is Madison Elementary School.

It is only seen a few times in the original series: in And Then There Were 10, Goodbye and Good Riddance, and Ben 10: Race Against Time. However, it is one of the main locations in Ben 10: Alien Force and Ben 10: Ultimate Alien, it also appeared on the Generator Rex episode Ben 10-Generator Rex: Heroes United.

Dwayne Mcduffie revealed that Bellwood's population is approximately 20,000 which explains why there are only 2 high schools (as revealed by Gwen).

Climate
Not much is revealed about it, but if you notice, it's always warm enough outside for characters to wear their current clothing. Evidence that their winters lack snow is expressed in Alien Swarm and The Final Battle: Part 2. It has a coast side climate.

Madison Elementary School
It is the main school of the city and also the school that Ben and Gwen used to go to before they grew up.

Ben 10
Referring to Goodbye and Good Riddance, Gwen was a transfer student. The school has only been seen three times in the series. The town also has two high schools; Ben and Gwen each go to separate ones. It has made many cameos throughout Alien Force and Ultimate Alien.

Hardware Store (Plumber Headquarters)
This headquarters was entered through an elevator that can be activated. This headquarters was full of pipes and seemed to be a center for pipes.

Under the city, it held the Hands of Armageddon which, when attacked, could cause natural disasters.

Diner

 * Le'Roys: In Ben 10: Race Against Time, Ben gets bullied by Cash and JT and two girls he tried to flirt with earlier in the movie resulting in Grey Matter causing complete chaos at a diner where Mrs. Dalton works.
 * Mr. Smoothie: The most common hangout for the trio. It is seen very often in Alien Force and ultimate alien.
 * Burger Shack: The restaurant that sells the chilli fries Albedo craves for. It is shown to be a self-service,dirty restaurant that is very crowded. Also, as heard in, “Good Copy, Bad Copy,” by an overweight cashier, having more than one order of chili fries per day can catch up to you. This is, assumingly how the cashier became overweight.

Undertown
Undertown is an underground alien city under Bellwood discovered first in The More Things Change: Part 1.

Allusions

 * There is a village in Illinois called Bellwood.