More than a dozen buildings have been added to English Heritage's latest "at risk" register for the Anglia region.
They include Langham Dome and Denver Mill in Norfolk, North Hertfordshire Masonic Lodge in Letchworth, St Peter's Church at Raunds in Northamptonshire, and Martello Tower at Felixstowe.
The register recognises buildings, structures and conservation areas which are at risk from decay, neglect or inappropriate change.
But it is better news for at least 11 sites in the region which have been taken off the list thanks to a programme of repair and refurbishment.
They include Finchingfield Guildhall in Essex, the Parish Church of All Saints at Weston, near Letchworth, and Clare Castle Keep in Suffolk.
Patrick Allen is from the Friends of Langham Dome.