It can also be translated as "kuta" or "kastilyo".
Here are some examples:
* "Ang tanggulan ay matatag at mahirap pasukin." (The fortress is strong and difficult to enter.)
* "Ang kuta ay itinayo noong panahon ng mga Espanyol." (The fortress was built during the Spanish era.)
* "May isang lumang kastilyo sa tuktok ng burol." (There is an old castle on top of the hill.)
The word you choose will depend on the context and the specific type of fortress you are referring to.