Old Bolingbroke gathers below the ruins of Bolingbroke Castle, a hexagonal fortress begun in the 13th century and birthplace of Henry Bolingbroke, later Henry IV, in 1367. The castle was slighted after a Civil War siege, so what remains is low walls and earthworks rather than towers, but you can walk the site freely at the foot of the Wolds. The market town of Spilsby is a few miles east.
© Bill Boaden / Geograph · CC BY-SA 2.0
