In its first phase of development, the town of Zug consisted only of a part of the present old town, which, however, had another third alley, which no longer exists today. Today's Untergasse still represented the middle alley until the catastrophe of the old town in 1435. The town area consisted of six approximately parallel rows of houses running southward.

Oldest known depiction of the town of Zug
from the chronicle of Johannes Stumpf (1547/48)