A gyro tower is a structure consisting of a tall stem along which a revolving disc rises and descends, carrying riders for amusement or observation. The disc where passengers ride is generally enclosed, with outward-facing seats arranged in a ring.

This structural form does not include towers or buildings with gyro towers built on the roof; at least 90% of the tower must be used as a shaft or cap for the movement of the observation disc.

The passenger disc both revolves and moves vertically along the stem. A rooftop installation on an otherwise occupiable tower does not meet the stated ninety-percent structural condition.