The Round House — so-called because of its doughnut-shaped appearance — is perhaps the most unusual building to be found on Tracy Island; and is accessed by a path running to the east of the main house (the Tracy Villa).
Built above a sunken, circular Oriental garden, this striking-looking structure provides additional accommodation, guest quarters and leisure facilities, comprising two levels of bedrooms and living areas. An additional, lower level includes utilities, a laundry room, and storage areas.
Like virtually everything else on Tracy Island, though, there's far more to the Round House than meets the eye: it's also the secret cover for Thunderbird 3's enormous, subterranean launch silo.
Thunderbirds Are GoEdit
In the movie Thunderbirds Are Go, the Round House looked rather different than it did in the TV series. It went from being a single-storey building to a two-storey one. The number of steps on the external stairway was greatly increased, whereas the height of the balustrade was decreased. Clearly, it was felt that the scale of the original building was incompatible with that of Thunderbird 3, a rocket which is said to measure 287 feet (c. 87 meters) in height.
- The general shape of Thunderbird 5 was based on the Round House, after several previous designs for it had already been rejected.
- A force-field and sensor array were built into the inner heat-resistant walls of the launch silo, to ensure Thunderbird 3 doesn't collide with the Round House when lifting off or returning to base.