The vault bundle cross-cut into the wall of the 3rd ventricle.
Columna fornicis in the wall of the 3rd ventricle.
The columnar part of the vault (columna fornicis) sinks into the wall of the 3rd ventricle below the ventricular interventricle (foramen interventriculare) and finds its way down through the hypothalamus and ends in the wart body (corpus mamillare).