Opposite the main entrance to the mansion is a large round building known as The Rotunda.
This was built in 1873, and it was used originally as a horse riding pavilion and exercise area.
Isaac Singer gave this building the nickname of “The Wigwam”.
It was used as offices in the late 1980s.
The main floor of the arena is removable and a swimming pool is below.
In 1914 Rotunda was used as a Hospital, so was the stables building for the war effort.