To paraphrase the late Douglas Adams, the American Museum of Natural History is big. Mind-bogglingly big. The museum complex comprises 45 permanent exhibition halls housed in 28 interconnected buildings, as well as a library and the Rose Centre for Earth and Space. The total floor-space is over 190,000 sq. m (2 million sq. ft) which can nevertheless display only a fraction of the museum’s 33 million specimens at any one time.