What rose above those forgotten graves in the second half of the thirteenth century was an unusual building for the Low Countries: a Turmburg, a tower castle. Most Dutch lords surrounded their keeps with curtain walls and outer defences; the keep was a last resort. Haamstede's builders did the opposite. They made the tower itself the refuge, twelve and a half meters by nearly nine, walls of red brick laid in Flemish bond, basement reachable only by descending from the floor above. If attackers got over the gatehouse and across the bailey, the family climbed inside the keep and waited. A portcullis dropped through grooves in the stone of a small gate building bolted directly to the tower. The basement could be sealed off entirely. Tower castles like this are rare in the Netherlands - cousins at Groesbeek, Geijsteren, and Ter Leede are all gone. Haamstede survives.

In February 1525, news arrived from northern Italy: the Holy Roman Emperor Charles V had crushed the French at the Battle of Pavia. Schouwen-Duiveland celebrated. Tar barrels were set blazing on the walls of the castle - by then expanded into a far larger second castle, four times the size of the original tower, complete with thick cannon-pierced walls and a heavy round tower jutting into the moat. Sparks drifted onto something flammable. Nobody noticed in time. The whole castle burned. When archaeologists came back in 1964, they found scorch marks on the thirteenth-century keep, where the fire had reached down through more than two centuries of additions. The bigger castle never came back. Only the old tower, with its impossibly thick walls, was worth rebuilding.

The names that ran through the deeds of Haamstede sound like a list of medieval intrigues, because that is what they are. In 1299 John I, Count of Holland, gave the castle to his dear brother Witte - bastard of Count Floris V, born around 1280, later celebrated in nineteenth-century legend for supposedly beating the Flemish in 1304 (a story now treated with caution). Witte's son Floris was killed near Warns in 1345. The Burgundian courtier and bibliophile Louis de Gruuthuse bought the castle in 1456 and probably built the larger fortress that the tar barrels would consume. His descendants ended up on the Spanish side of the Eighty Years' War; the States of Zeeland confiscated Haamstede in 1583. The poet and army captain Jacob van den Eynde took it on in 1609, and gave the castle the silhouette it largely keeps today.

In 1981 the castle passed to Natuurmonumenten, the Dutch nature conservation society. The family that had lived there retained the right to keep doing so. Around the keep, oak and beech woods spread across former parkland, and the moat reflects whatever Schouwen's wide skies happen to be showing. The grounds are now a sanctuary for owls, and on a still evening you might hear tawny calls echoing off brickwork that has been standing for over seven hundred years. A short walk south, the dunes drop down to the long beaches of the North Sea coast, where holidaymakers in Burgh-Haamstede have no idea that the quiet wood-fringed castle behind them is built on someone's Carolingian-era cemetery.