The Museum Building, which houses the Geology Department, was designed by Thomas Deane and Benjamin Woodward. It is inspired by the Byzantine architecture of Venice and was built in 1853-57. The many interior and exterior carvings were executed by the Cork-born brothers John and James O'Shea, who gathered fresh flowers to use as their models. The exterior walls feature Wicklow granite and Portland Stone.
The interior walls are faced with Caen Limestone. The pillars, balustrades and bannisters contain examples of Irish marbles and Cornish serpentine, while the domed roof is made of blue, red and yellow enamelled bricks.