A brief account is given of current research upon Middle Pleistocene deposits exposed in a working limestone quarry near Westbury-sub-Mendip, Somerset. The geology and fossil mammal content are outlined and show the deposits divisibvle into an upper group formed in a cave environment and a lower group of waterlaid deposits washed in from outside. Stratified deposits representing the cave environment contain rich temperate mammalian fauna no later than Elserian (Anglain) in age. The underlying waterlaid deposits represent an earlier climatic phase, containing a sparse mammalian fauna no later than ‘Cromerian’ in age, but probably not as early as the pre-glacial Lower Pleistocene. Several mammal species are recorded from this site for the first time in Britain.