Bangor (pop. 32,000) is close to the center of the state as well as along the only interstate (I-95) in Maine. It is considered the gateway to northern Maine which is often called the Katahdin Region (for the largest mountain in Maine).
Given its population, Bangor seems much larger. Author Stephen King reportedly lives in the area.
Traffic in downtown Bangor can be quite a mess. Streets go in every direction, some are one-ways. Tough to drive in for a newcomer.