Town 11 is a Large Map without decoration such as buildings, sidewalks or vegetation. The road network consists of sprawling single lane roads interspersed with small clusters of grided junctions. The landscape has some hills and elevations and has a grass-like texture.
Town 11 principally serves as a proof of concept for the Large Map functionality introduced in CARLA 0.9.12 and was the first Large Map to be integrated into the CARLA simulator. You may find it helpful to look at Town 11's asset files in the Unreal Editor to understand how large maps are handled within the CARLA ecosystem.