 The building originally housed the University's Arts, Science and Medicine departments.The main entrance is on floor C, from this point up there are four complete floors (up to F floor which houses the first of the MBB lecture theatres (F2) and research labs) and then G floor which is divided into several sections (housing the second lecture theatre (G2) and seminar rooms).This gives the five floors sometimes quoted, however the department's NMR facility extends downwards from floor C and is housed on B (which is ground level at the back of the building), A and a further floor below this which has no official designation.