The vestibule is an approximately 4 mm central chamber of the bony labyrinth. It is dominated by depressions housing parts of the membranous labyrinth:
utricle (elliptical recess)
saccule (spherical recess)
basal end of the cochlear duct (cochlear recess)
It is located medial to the tympanic cavity, posterior to the cochlea and anterior to the semicircular canals. In the lateral wall is the oval window with the stapes foot plate covering it.
The cribrose areas have perforations through which the nerve bundles gain access to the inner ear. The endolymphatic duct is housed within the bony vestibular aqueduct and originates at the posteroinferior aspect of the vestibule, via the utriculosaccular duct.