The location moves to another Kentucky cave, this one called Horse Cave, located in the town of the same name. This image is of a mass of stone which has formed from stalactites into a single object, and is not supported from below, thus the name Hanging Bridge.
The description states:
HANGING BRIDGE, MAMMOTH ONYX CAVE
HORSE CAVE, KENTUCKY
This is one f the most perfect of several large suspended masses of cave onyx unique in this Fairyland of KENTUCKY. Its weight exceeds 75 tons.
–This cave is located in the center of the town of the same name, and provided water, electrical power and natural air conditioning in years past. This card likely dates from the 1950s.