New York City Water Tunnel No. 3 Ventilation Towers

City Tunnel No. 3 has been under construction since 1970 (for more information see my other post about the tunnel).  Each shaft has a ventilation tower.  Originally, the sidewalk entry door for each shaft, (some as deep as 1000 feet), was labelled with the shaft number.  These were removed after 9/11/01.  But they can still located by their distinctive ventilation towers.  The towers are not identical, but have a consistent style.  Once you've seen these you should be able to recognize others.

Shaft 14b, New York

Shaft 19b, Brooklyn

Shaft 16b, Queens

Shaft 23b, Brooklyn

Shaft 11b, New York

Shaft 20b, Brooklyn