Quite a few villages, towns and cities have their name ending in -ingen: Sigmaringen, Singen, Villingen-Schwenningen (combo), Donaueschingen, Memmingen, Tübingen, Überlingen, Uhldingen. I could go on and on.
What is the origin and the meaning of this suffix?
From experience, I think this is prevalent in Baden-Württemberg. Could it be a Swabian thing?