The oldest parts of the castle include the Great Hall and the 14th-century pele tower, a type of watch-tower fortification unique to the English-Scottish border region.

[6] Muncaster's gardens include features designed to take advantage of views of the Esk Valley and the mountains.

Since 2021, the owners are Peter and Iona Frost-Pennington, with their elder son Ewan the "Muncaster's operations director".

[11] In October 2021, the castle was one of 142 sites across England to receive part of a £35-million injection into the government's Culture Recovery Fund.

After the Battle of Towton in 1461, according to tradition, Henry VI fled to Muncaster Castle where Sir John Pennington sheltered him.

He is rumoured to have said, "There, I have hid Dick’s head under a heap of shavings; and he will not find that so easily, when he awakes, as he did my shillings.