The Thorndyke Mansion, also referred to as the Thorndyke Estate or the Thorndyke Residence, is a residence in the Sonic X anime series and in the comic series of the same name. It is the luxurious home of Christopher Thorndyke, his parents, Chuck Thorndyke, Ella and Mr. Tanaka. When Sonic the Hedgehog and most of his friends were stranded on Earth, they took residence at this mansion for the majority of their stay.
The Thorndyke Mansion is a beautiful building with several luxurious details covering several acres of land, presumably due to Nelson and Linsey Thorndyke's successful careers. The mansion itself is a two-story white building with several black windows, balconies, a red roof and its front door area is sheltered with four pillars supporting the shelter onto the main road via steps. A small pond is located in the middle of the front door area. The mansion is surrounded by a large flat turf embarked with small trees and hedges and there is a pathway leading to the outdoor swimming pools and a sheltered pathway leading to the garage.
The mansion's garage is the area where Sonic's friends and Chuck normally hang around. Beneath it, Chuck has a built-in secret laboratory where most of his creations are constructed at such as the X Tornado. The road leading from the garage is styled like a runway from an airport with palm trees located on its sideways where the X Tornado usually takes off.
Years ago, Chris and his parents settled into the mansion. Despite his luxurious lifestyle, Chris felt very lonely since his parents were constantly busy because of their careers, leaving him alone at the mansion with Chuck, Ella and Mr. Tanaka, though they were able to occasionally visit him.
After outrunning the police forces and the Speed Team, Sonic the Hedgehog first discovered the Thorndyke Mansion when he flew through the air only to land right in one of the mansion's outdoor pools. As Sonic tried to escape the pool, he was rescued by Chris and was allowed to stay at the mansion. Later on, Sonic saved Tails, Cream, Cheese and Amy following their arrival on Earth, and they all agreed to settle into the Thorndyke Mansion as their new residence on Earth.
Initially, due to their special characteristics, Sonic and his friends had to remain hidden from Mr. Tanaka and Ella so they mainly resided in Chuck's laboratory when they were not out stopping Dr. Eggman from achieving world domination.
One day, Mr. Tanaka told Chris that his parents were coming to visit, feeling both excited and nervous since he had to remind Sonic and his friends to stay hidden before heading for school. During the day, Nelson and Lindsey arrived at the mansion, awaiting Chris' return, but when he did not return after a long time, the entire family began to feel worried. Thanks to Sonic though, Chris came home and enjoyed a nice dinner with his family at the mansion during the evening.
After coming home, Lindsey decided to hold a party at the mansion to celebrating her return home. The party did not go as expected though, as Cream and Cheese volunteer to help with the party despite Chris telling them to remain hidden. Also, when Lindsey got herself ready, she was forced to leave to star in another movie. During the party, Sonic and his friends unintentionally reveal themselves despite Chris, Chuck and Mr. Tanaka's attempts to fool the guests that they did not exist. Eventually, Chris told Ella the whole story, which made Ella aware of the existence of Sonic and his friends.
One late night, Sam Speed, the leader of the S-Team visited the mansion to issue a race against Sonic, with the mansion serving as the start of the race. When Sonic and co. tried to object, a large throng of people standing outside by the mansion's gates had amassed and waiting for the race, which Sonic, after a long process of persuasion, finally accepted.
Later on, another large crowd of people gathered outside of the mansion's gates to praise Tails for heroically disarming a missile. However, since Tails rather wanted to find the X Tornado when it got missing, Chuck had the idea of Ella and Mr. Tanaka distracting the crowd by dressing Tanaka as a baby and hide him in a pram Ella drove so the crowd would think Tails was hiding there while Tails escaped unnoticed. When Ella left the mansion with Tanaka in the pram, the plan worked perfectly, and Tails fled when the coast was clear.