Castletown Estate was purchased in 1802 by Robert Mounsey and has remained in the Mounsey family ever since. Completed in 1811, the house is a well-proportioned mansion, which stands magnificently within the grounds of the Estate.
​
The house sits back from the banks of the River Eden, with stunning views across parkland and onto the village of Rockcliffe.
​
It was designed and built by the distinguished architect Peter Nicholson, whom whilst in the area remodelled Corby Castle and over looked the erection of the Court Houses in Carlisle.
The house was listed as a Grade II building in 1957 and has been carefully looked after by eight generations of Mounsey-Heyshams.


The Estate covers an expanse of approximately 4,000 acres, half of which is marshland (Rockcliffe Salt Marsh) while the other half is in-land fields – both used for farming.
The border of the estate is at the confluence of two rivers, the Eden entering from the south and the Esk from the North. Between these two rivers is a variety of land and farming opportunities, a wild and dynamic expanse of estuary, mudflats and marsh which detail is restlessly redrawn by the tidal ebb and flow.
​
Castletown is currently occupied by Giles and Penelope Mounsey-Heysham, but their eldest son, Toby, and his family will be moving into the house in the coming years, becoming the ninth generation to live there.