Ionic column

An Ionic column describes a piece of architecture that the Master used to disguise his TARDIS as utilising his functional chameleon circuit. (DW: Logopolis) The Doctor's TARDIS did, prior to its chameleon circuit malfunctioning, take the shape of an ionic column. (DW: An Unearthly Child)

This is actually a Doric column, contrary to popular belief. Ionic columns are much more decorative.