The whole site was attacked by bombardment and mining and it is not known how much was left standing. The present 'castle' - more of a fortified tower house rather than a defensive keep - appears more or less in its present state in engravings of the 18th century. In its time it has been owned by a number of families.
The Hopton Castle Preservation Trust has campaigned over many years to purchase and rescue what remains of this unique and fragile site. Agreements with Heritage Lottery Fund, English Heritage and other agencies since 2007 have secured more than £1million for a three year project which will purchase and consolidate the site and provide information about and access to this remarkable remnant of a siege which earned an unenviable place in Parliamentarian accounts of the Civil War.
Hopton Castle has important historical and literary connections. The Civil War garrison was closely linked to another Parliamentarian stronghold 3 miles south at Brampton Bryan. Lady Brilliana Harley, wife of the Earl of Oxford, sat through part of the siege at Brampton in the year after Hopton's. Her correspondence with her soldier husband and son is renowned for the insights it offers into a wealthy and well-connected household of the period.
The prize-winning author Kevin Crossley-Holland has set his Arthur trilogy in the area. The young medieval hero, Arthur, is born in a fictionalised Hopton Castle.