Baconsthorpe Castle
Norfolk, England
Balvaird Castle
Perth and Kinross, Scotland
Complete late-medieval tower house; exterior open year-round
Berkhamsted Castle
Hertfordshire, England
Managed with Berkhamsted Castle Trust; open daily
Berwick-upon-Tweed Castle and Ramparts
Northumberland, England
Bramber Castle
West Sussex, England
also listed under National Trust
Burgh Castle Roman Fort
Norfolk, England
Saxon Shore fort; managed by Norfolk Archaeological Trust
Burleigh Castle
Perth and Kinross, Scotland
Free; open Apr-Sep on set days
Carnasserie Castle
Argyll and Bute, Scotland
Free; overlooks Kilmartin Glen
Carsluith Castle
Dumfries and Galloway, Scotland
Free 16th-century tower house beside Wigtown Bay
Castell Dinas Bran
Denbighshire, Wales
Hilltop ruin above Llangollen; free, steep walk
Castle Sween
Argyll and Bute, Scotland
Free; possibly Scotland's oldest standing castle
Castle of Old Wick
Highland, Scotland
Free; Norse-era tower on cliff-edge promontory
Cromwell's Castle
Cornwall, England
17th-century gun tower on Tresco, Isles of Scilly
Crookston Castle
Glasgow City, Scotland
Glasgow's only medieval castle; free entry; also listed under National Trust for Scotland
Cubbie Roo's Castle
Orkney Islands, Scotland
Scotland's earliest stone castle, on island of Wyre
Deddington Castle
Oxfordshire, England
Earthworks only
Drumcoltran Tower
Dumfries and Galloway, Scotland
Free tower house standing in a farmyard
Duffus Castle
Moray, Scotland
Free; fine motte-and-bailey with later stone tower
Dunseverick Castle
County Antrim, Northern Ireland
Scant gatehouse ruin on Causeway Coast promontory
Edlingham Castle
Northumberland, England
Egremont Castle
Cumbria, England
Free access ruin in public park
Etal Castle
Northumberland, England
Free entry; shop and museum now closed
Greenknowe Tower
Scottish Borders, Scotland
Free 16th-century L-plan tower near Gordon
Hadleigh Castle
Essex, England
Hailes Castle
East Lothian, Scotland
Free riverside fortified manor, open year-round
Haverfordwest Castle
Pembrokeshire, Wales
Inner ward free daily; town museum adjacent
Knaresborough Castle
North Yorkshire, England
Free grounds; keep and museum seasonal
Loch Doon Castle
East Ayrshire, Scotland
Free; eleven-sided curtain wall relocated in 1935
Lochmaben Castle
Dumfries and Galloway, Scotland
Free lochside ruin linked to Robert the Bruce
Lochranza Castle
North Ayrshire, Scotland
Free tower house on Arran promontory
Marisco Castle
Devon, England
On NT-owned Lundy; Landmark Trust manages, keep cottages via Landmark
Monea Castle
County Fermanagh, Northern Ireland
Free plantation castle ruin on private farmland; closed Dec-Jan
Moreton Corbet Castle
Shropshire, England
Medieval castle and Elizabethan mansion ruins
Morton Castle
Dumfries and Galloway, Scotland
Free remote hall-house above an artificial loch
Muness Castle
Shetland Islands, Scotland
Britain's most northerly castle, on Unst; free
Newark Castle
Nottinghamshire, England
Free gardens; gatehouse tours select days
Noltland Castle
Orkney Islands, Scotland
On Westray; free, famed for 71 gun holes
Norham Castle
Northumberland, England
Free; open daily in season; some areas closed
Odiham Castle
Hampshire, England
King John's octagonal keep, free access
Orchardton Tower
Dumfries and Galloway, Scotland
Scotland's only free-standing round tower house; free
Penrith Castle
Cumbria, England
Ruin in public park
Piel Castle
Cumbria, England
On Piel Island; seasonal ferry from Roa Island
Pontefract Castle
West Yorkshire, England
Free entry with visitor centre
Ravenscraig Castle
Fife, Scotland
Early artillery castle; grounds open, tower interiors restricted
Scalloway Castle
Shetland Islands, Scotland
Free; key available locally if locked
Skipness Castle and Chapel
Argyll and Bute, Scotland
Free castle with 16th-century tower house, Kintyre
Spofforth Castle
North Yorkshire, England
St Catherine's Castle
Cornwall, England
Small Henrician fort above Fowey
Strome Castle
Highland, Scotland
Ruin on Loch Carron shore; free, open at all times
Sutton Valence Castle
Kent, England
Tully Castle
County Fermanagh, Northern Ireland
Plantation castle and garden; seasonal visitor centre
Weeting Castle
Norfolk, England
Wolvesey Castle (Old Bishop's Palace)
Hampshire, England