sentences:  Features like machicolations and improved arrowslits became also widespread.Starting in the 14th century, keep towers became larger and more sophisticated, with rib vaulting roofs and facilities like fireplaces.Keep towers with improved residential characteristics can be found in the castles of Beja, Estremoz and Bragança, while some later castles (15th century) became real palaces, like those in Penedono, Ourém and Porto de Mós.