Complex sentence: The original Spiegeltents were constructed in the Flemish Region of Belgium in the late 19th century as mobile dance halls intended to travel around the country to town fairs which did not have a proper dance hall.
Split into simpler sentences: The original Spiegeltents were constructed in the Flemish Region of Belgium in the late 19th century as mobile dance halls. They were transported around the country and assembled for town fairs in areas that did not have a proper dance hall.