Montreal
Montreal is a city in the Canadian province of Quebec and is believed to be part of where the Interface series takes place due to similarities found in the landmarks and their real-life counterparts. It currently also happens to be the city where 'U M A M I' lives.
Interface Episode 02
In Episode 02 of Interface, "Mischief" transforms into a bus and takes "Blue Guy" around what seems to be Montreal to the Montreal Fine Arts Museum. They pass many landmarks on their way that look very similar to those found in real life Montreal.
Based on the orders of the Landmarks seen, this is one of the routes they likely took through the city.
Similarities
The Mount Royal Cross in Montreal
The Mount Royal Cross as Appears in Ep 02 of Interface
The Montreal Olympic Park, host of the 1976 Summer Games
The Montreal Olympic Park as appears in Ep 02 of Interface
The Montreal Museum of Fine Arts as appears in Ep 02 and 05 of Interface
The Montreal Museum of Finearts
The Montreal Interchange
The Montreal Interchange as appears in Ep 02 of Interface