Believe it or not, this used to be a jaguar exhibit. And yes it was enclosed like that - no open top. It was one of the last old style exhibits to be closed in their move to modernize. When I first visited Tucson in 1992 it was still a jaguar exhibit. When I moved to Tucson in 1993 the jaguar had presumably died and it had been converted to this entry plaza. Ever since then they periodically mention bringing jaguars back to the museum, but it's been almost three decades and it hasn't happened yet.