In 1761, the North East Tower of the Palace was demolished and the stonework carried to Knole, Sevenoaks, where it was used to build Knole Folly which lies to the South-East of Knole House.
(Image by Pete Chapman [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons)
The arch at Knole is part of a sham ruin that was probably built at the same time as the Bird House in 1761 with masonry from the North East Tower of Otford Place. Bird House itself is a revival style building it intended to house Lionel, first Duke of Dorset’s exotic bird collection. It is now a private home for an estate worker and is not open to the public