Certain |
Possible |
Questionable Doubtful |
Rejected |
|
Confidence is a statement of the site as a medieval fortification or palace |
| Name | Alternative Name(s) | Type | Remains |
| Ancaster | Oncaster; Onkaster | Timber Castle | Earthworks |
| Aslackby Castle | Fortified Manor House | Cropmarks/slight earthworks | Aslackby Preceptory | Temple Farm | Fortified Ecclesiastical site | Nothing visible |
| Barrow upon Humber; The Castles | Goxhill | Timber Castle | Earthworks |
| Barton upon Humber Castle | Timber Castle | Nothing visible | |
| Barton upon Humber Town Rampart | Urban Defence | Nothing visible | Belleau Manor | Fortified Manor House | Masonry ruins/remnants | Benniworth Castle | Beningwrd' | Timber Castle | Cropmarks/slight earthworks | Bishop Norton Manor | Moat Farm; Stowe | Palace | Nothing visible |
| Bolingbroke Castle | Masonry Castle | Masonry footings | |
| Boothby Pagnell Manor | Fortified Manor House | Major | Boston Town Defences | Urban Defence | Cropmarks/slight earthworks |
| Bourne Castle | Brune | Timber Castle | Earthworks | Bourne Village Defences | Urban Defence | Cropmarks/slight earthworks | Broughton, Lincolnshire | Timber Castle | Cropmarks/slight earthworks |
| Burton Pedwardine | Timber Castle | Earthworks | Butterwick Tower | Tower House | Nothing visible |
| Caistor | Castor | Masonry Castle | Nothing visible | Caistor Castle Hill | Castor | Timber Castle | Nothing visible | Caistor Town Defences | Castor | Urban Defence | Nothing visible | Casewick Hall, Uffington | Fortified Manor House | Nothing visible |
| Castle Bytham | Biham; Bitham | Timber Castle Masonry Castle |
Earthworks |
| Castle Bytham Village Defences | Biham | Urban Defence | Earthworks |
| Castle Carlton Borough Defences | Market Carlton | Urban Defence | Earthworks |
| Castle Carlton, South Reston | Timber Castle | Earthworks | Castlethorpe, Broughton, Lincolnshire | Masonry Castle | Cropmarks/slight earthworks | Caythorpe Manor | Fortified Manor House | Cropmarks/slight earthworks |
| Corby Glen Motte | Timber Castle | Earthworks | |
| Countess Close, Alkborough | Fortified Manor House | Earthworks | Dalby, Old Hall Holt | Partney | Timber Castle | Cropmarks/slight earthworks | Dewy Hill | Dewey Hill | Timber Castle | Cropmarks/slight earthworks | Eagle Preceptory | Aycle | Fortified Manor House Fortified Ecclesiastical site |
Earthworks | Epworth | Fortified Manor House | Nothing visible |
| Eresby Manor | Eresby Hall | Fortified Manor House | Masonry footings | Fleet Motte | Timber Castle | Cropmarks/slight earthworks |
| Folkingham Castle | Folkyngham | Timber Castle Masonry Castle |
Earthworks | Frampton Castle | Timber Castle | Cropmarks/slight earthworks |
| Friskney Abbey Hills | Fortified Manor House | Earthworks | Friskney Hall | Friskeneye | Fortified Manor House | Earthworks |
| Friskney Manor House | Fortified Manor House | Earthworks | Gainsborough Old Hall | Fortified Manor House | Nothing visible |
| Gainsborough Park | Lea | Fortified Manor House | Cropmarks/slight earthworks |
| Goltho Manor | Timber Castle | Cropmarks/slight earthworks | |
| Grantham Castle | Timber Castle Masonry Castle |
Nothing visible | |
| Grantham Town Defences | Urban Defence | Nothing visible | Grimsby Castle | Masonry Castle | Nothing visible |
| Grimsby Town Walls | Urban Defence | Nothing visible | Grimsthorpe Castle | Masonry Castle | Masonry ruins/remnants | Halstead Hall | Fortified Manor House | Earthworks |
| Heydour Castle Hills | Timber Castle | Earthworks | Holme Spinney, Beckingham | Timber Castle | Cropmarks/slight earthworks |
| Holywell Castle Dyke | Aunby | Timber Castle | Earthworks | Horncastle Bishops Palace | Palace | Nothing visible | Horncastle Castle | Timber Castle | Masonry ruins/remnants |
| Hough on the Hill Castle Hill | Timber Castle | Earthworks | Hougham Manor | Fortified Manor House | Nothing visible |
| Hussey Tower | Tower House | Major | Kettlethorpe Hall | Fortified Manor House | Earthworks |
| Kinaird Castle, Owston Ferry | Kinnards Ferry; Axholme; Kenefar; Kinardferry | Timber Castle | Earthworks |
| Kingerby Hall | Timber Castle | Cropmarks/slight earthworks | |
| Kingerby Village Defences | Urban Defence | Nothing visible | |
| Legsby; The Mount | Timber Castle | Earthworks | Lincoln Bishops Palace | Palace | Masonry ruins/remnants |
| Lincoln Castle | Timber Castle Masonry Castle |
Major | |
| Lincoln Cathedral Close | Fortified Ecclesiastical site | Masonry ruins/remnants | |
| Lincoln City Wall | Urban Defence | Masonry ruins/remnants | |
| Lincoln siege-works | Siege Work | Nothing visible | Louth Bishops Manor | Palace | Nothing visible | Ludham Hall | Palace | Nothing visible | Mablethorpe | Malberthorpe | Fortified Manor House | Earthworks | Moulton, Kings Hall | Kings Hall Park; Quapelode; Whaplode | Timber Castle Masonry Castle |
Earthworks |
| Nettleham Bishops Manor | Langworth; Netelham | Palace Fortified Manor House |
Earthworks | Newhouse Castle | Newsham; Goxhill | Timber Castle | Uncertain | Old Skegness Castle | Timber Castle | Nothing visible | Old Skegness Town Defences | Urban Defence | Nothing visible | Partney Castle | Timber Castle | Uncertain |
| Redbourne Castle Hills | Timber Castle | Cropmarks/slight earthworks | |
| Rochford Tower | Kyme Tower; Richmond Tower; Skirbeck | Tower House | Major | Scrivelsby Court | Scrivelsby Hall | Masonry Castle | Masonry ruins/remnants |
| Sleaford Castle | Lafford; Sleford | Masonry Castle Palace |
Earthworks |
| Somerton Castle, Lincolnshire | Masonry Castle | Masonry ruins/remnants | |
| South Kyme Tower | Tower House | Major | South Witham | Fortified Manor House | Nothing visible | Spalding Castle | Timber Castle | Nothing visible | Spalding Priory | Spaldyng | Fortified Ecclesiastical site | Nothing visible |
| Stainby Tower Hill | Timber Castle | Earthworks | |
| Stamford Castle | Masonry Castle | Masonry ruins/remnants | |
| Stamford Town Wall | Urban Defence | Masonry ruins/remnants | |
| Stow Bishops Palace | Moat Farm; Stowe | Palace | Earthworks |
| Swineshead; The Manwarings | Baythorpe; Manwar Ings | Timber Castle | Earthworks |
| Tattershall Castle | Tateshal | Masonry Castle | Major | Temple Bruer Preceptory | la Bruere | Fortified Ecclesiastical site | Masonry ruins/remnants |
| Thonock Castle Hills | Gainsborough | Timber Castle | Cropmarks/slight earthworks | Thorngate, Lincoln | Tornegat | Timber Castle | Nothing visible |
| Thornton Abbey | Fortified Ecclesiastical site | Major | |
| Toot Hill, Tothill | Timber Castle | Earthworks | |
| Topclyve | Timber Castle | Uncertain | Torksey Castle | Windmill Hill | Timber Castle | Nothing visible |
| Tower on the Moor | Woodhall | Tower House | Masonry ruins/remnants |
| Trehampton Manor, Lea | Hermit Dam Wood; la Lee | Fortified Manor House | Earthworks |
| Wainfleet Castle Hill | Timber Castle | Nothing visible | |
| Welbourn Castle Hill | Welbourne | Timber Castle Masonry Castle |
Earthworks |
| Welton le Marsh Castle Hill | Hanby | Timber Castle | Cropmarks/slight earthworks | Withern Castle Hill | Timber Castle | Earthworks | Wragby Rout Yard | Timber Castle | Earthworks |
| Wrangle Kings Hill | Timber Castle | Cropmarks/slight earthworks | Wyberts Castle, Wyberton | Wells Slade | Timber Castle | Cropmarks/slight earthworks |