Name: Bolingbroke Castle, Old Bolingbroke
Address: Moat Lane, Old Bolingbroke, Lincolnshire, PE23 4HH

Tucked into a quiet valley on the southern edge of the Lincolnshire Wolds, three miles east of Spilsby, Bolingbroke Castle is one of the county’s most atmospheric ruins — and the birthplace of a king.

The castle was raised around 1220 by Ranulf de Blondeville, Earl of Chester and Lincoln, one of three he built after returning from crusade. Its unusual hexagonal plan enclosed a courtyard behind five round towers and a substantial gatehouse, the whole thing built largely of local Spilsby greenstone and ringed by a broad water-filled moat. Marriage carried the estate into the House of Lancaster, and by the 14th century it belonged to John of Gaunt — whose son Henry Bolingbroke was born here in 1367, going on to seize the throne as Henry IV. The castle later served as an administrative headquarters for the Duchy of Lancaster’s vast Lincolnshire holdings.

By 1636 the towers were reported beyond saving, but the Civil War gave the old fortress one last chapter: a Royalist force occupied it in 1643 and held out for weeks before surrendering in November, in the aftermath of the Battle of Winceby fought a few miles away. Parliament ordered it slighted in 1652, and the towers and walls were pushed into the moat to stop it ever being defended again. Excavation in the 1960’s and 70’s brought the plan back into the light.

Visiting Today

What survives is the lower courses of the walls and the ground floors of the towers, but the scale is unmistakable: you can walk the full hexagon, cross where the drawbridge once stood and follow the moat right around. Entry is free and the site is open at any reasonable time during daylight hours, with a small car park on Moat Lane (PE23 4HH). Interpretation panels around the site explain the history and the archaeology, and the neighbouring field with its earthworks is open too. There are no toilets or refreshments on site. Dogs on leads are welcome. Paths are cut through the grass, but the ground is uneven and there is deep water in the moat, so take care with children. The castle also hosts events through the summer, including open-air Shakespeare.

The site is cared for by Heritage Lincolnshire on behalf of English Heritage. Combine it with the village church of St Peter and St Paul, John of Gaunt’s church, a short walk away.