This is the ceiling of the 105 year-old, 70 ft. tall Elephant House. This is the gap between Jati and Sabu\'s exhibit and My-Thai\'s and Schottzie\'s exhibit. It used to be the gap between the giraffe and okapi exhibits and the elephants.
OK, here's more:
The architects had built America's first re-inforced concrete skyscraper in Cincinnati three years earlier. That experience enabled them to design this concrete building which opened in 1906. The Herbivora was situated on the zoo's highest point so it could be seen from a great distance as an attraction to visitors. It originally cost USD50,000
(taken from Dave Ehrlinger's terrific book The Cincinnati Zoo and Botanical Gardens, From Past to Present 1993)