One of the oldest surviving buildings in the town centre. Number 11 (actually numbered 11 and a half) was built in 1758 and served as the town hall for a period. It has an arched pend leading to a small courtyard/garden at the rear. The building is currently home to Port Glasgow Old People's Welfare Council.
The building and its neighbour at number 9 are described by the British Listed Buildings website
Link as follows...
"2-storey rubble, part stuccoed later: main part 7-windows
with quoins margins and eaves cornice: segmental pend
arch with in and out voussoirs; 5-window S. section with
triple keystones and skewputts. Mid 18th cent."