This is at the wonderful University Museum of Natural History in Oxford. Not only is it a perfect small museum, featuring a contained but coherent collection of consistent high quality but it is also housed in a single room, or court, that reamins a monument to Victorian techno-gothicism. The columns and soaring tracery in the foreground are all iron -- state of the art in 1860.
The muesum contains what remains of the Tradescants' original natural history collection that began the Ashmolean. It was also the site of the famous Oxford Evolution Debate between Huxley and Wilberforce, among others.