This small building called the Grotto (listed Grade II) was built by Sir Daniel Fleming in 1668-9. He referred to it in his accounts as the Grot and "My Grott House". It is a simple stone building with a door on the south side and a window on the north side giving a view of the waterfall, the plunge pool and the bridge. The interior was originally panelled and the accounts show that this and the glazing, cost more than the rest of the building.
The building is unique and is Britain's earliest known purpose built viewing station.