Mount Warrnambool is a single large scoria cone volcano that is 216 metres (709 ft) high. It is 16 kilometres (10 mi) southwest of Terang, Victoria, Australia. It is visible from the Princes Highway on the way to Warrnambool.
The last eruption of Mount Warrnambool was over 5,000 years ago. Lava and tuff form layers in the area. The tuff forms a partial ring around the east and north sides of the volcano. The ring of tuff could be on other sides of the volcano too, except that it is covered in lava. The tuff has been quarried on the north side of the Princes Highway. The tuff here is hardened, but was formed due to volcanic ash falling from the air. Structures visible in the quarry include a base surge and volcanic bomb sag.