Kenilworth Castle 

Kenilworth castle was first built in about 1122,with a basic square keep, which is now known as the Strong Tower, inside a protective curtain wall.
Then in the thirteenth century King John, added an outer perimeter wall, part of which was defended by Lunn's Tower.  The John of Gaunt improved it further in about 1400, developing the domestic buildings and creating a palace over looking the lake.
Then later, in Tudor times, the Earl of Leicester erected extra lodgings ...
a magnificent gatehouse ...
and some stables, so that he had a palace fit to entertain Queen Elizabeth I. It survived the Civil Way and now it is managed by English Heritage as part of our national heritage.