Slighted

When the king ordered castles to be slighted, he wanted them razed to the ground, but sometimes the task was too much and the demolition gang took down only part of the walls. Before the castle could be used defensibly, it had to be restored.
Knights came back from the crusades with ideas about buildings, ideas they’d seen first hand in the Holy Land.
In Romanesque castles and churches, windows were built with rounded arches and passages were roofed with barrel-vaults or groined vaults. Pointed arches suddenly appeared, and Gothic was here to stay. A pointed arch was found to be far more flexible architecturally, and led to rib-vaulting, first used in Durham Cathedral before 1133.
Castles became circular in shape, because the right-angled corner of the old square keeps was all too easy to undermine, and defenders could only see straight ahead through the narrow window slits. Circular castles, with towers that commanded views of all parts made defence easier, and attack harder. Castles built in Henry II’s reign incorporated these new ideas, and often added in small kitchens for making sauces and keeping food hot. Big outdoor timber kitchens still coped with the roasts and the bulk of the cooking.

The pic is Elsdon Bastle House, now a private dwelling.