D Shaped Keeps

D shaped keeps are not common structures in Europe before the fourteenth century, but most examples can be found in a handful of mainly Welsh built fortresses.

England
Helmsley

Wales
Caerwgle, Cardigan, Carndochan, Chepstow, Dinas Bran (rectangular curtain too), Ewloe, Grosmont, Llandovery, Llangibby, Montgomery (a normal mural tower?), Newport, Roche, Sennybridge, Tenby, Y Bere, Ystradfellte

France
Ballon