The fort that has trenches all around it is called ______ fort.

According to the traditional classification of forts, a fort that is surrounded by a moat or trench on all sides is known as a Parikh Fort (Parikh Durg). The term "Parikh" is derived from the word Parikha, which means a moat or ditch constructed around a fort for defense purposes. Such moats acted as protective barriers against enemy attacks.

Therefore, the correct answer is Parikh.