San Diego first to have open-air grottoes

San Diego was the first zoo in the U.S. to exhibit animals in open-air grottoes, in 1923. As often happened in the early days, things got made up on the fly.

They needed a grotto for Caesar the bear because she kept wrecking her cage. But they didn’t have enough money, so they decided they could do without a cement floor. The soil would be too hard for the bear to dig through, they figured.

Caesar spent her first night in the grotto digging a tunnel big enough to drive a truck through. She’d tossed aside concrete reinforcing the back of the grotto, piled dirt up against a fence and was standing there when she was spotted. The excavation was “something we could not have duplicated without dynamite,” zoo founder Dr. Harry Wegeforth later wrote. They never again took shortcuts with the flooring.

The second grotto was for the lions. Wegeforth wasn’t sure how deep they needed to dig the pit so he had a film company in Hollywood do tests for him. They tied meat to the end of a rope and dangled it over a trained lion to see how high it could jump.

When it opened, the exhibit became home to a male lion named Prince and pride mates Cleo and Queen.