The Rhoades Mansion is an important location in the world of Spectral Shadows, being the setting for a
couple of serials such as Serial 8 "The House of Spectral Shadows", and at the very least being an important location such as with Serial 11 "The Planet of Genetic Misadventure". The mansion itself is often described as being rather Gothic looking, haunted, and being bigger on the inside and a place that's incredibly easy to get lost in. In Serial 11 it's revealed that The Rhoades Mansion is actually Captain Shane's SoundChaser, Rociante. By the time Serial 11 happens Sir Jon is a retired Time Captain who is the owner of the Rociante. It is also revealed that The Rhoades Mansion on Cygnus is the very same Rhoades Mansion that Christine James and her family lived in the past.
There are many secret passages, hidden locations, and rooms of note in The Rhoades Mansion such as a hidden bathhouse, the inner workings and controls of Rociante, the power core of the SoundChaser itself, and the Hall of Portraits.
The inspiration for The Rhoades Mansion comes from a couple different shows, namely Collinwood Mansion from the Gothic soap opera Dark Shadows, and the TARDIS from Dr. Who (which are also themselves inspiration for SoundChasers).