A stronghold is a place that is very safe and protected, especially from attack. It can be a building or a part of a city or country.
A stronghold can make people think of power, safety, and control.
Examples:
The castle was a stronghold for the king.
The fort was a stronghold for the soldiers.
The stronghold was very big and had many walls.
The treehouse was our secret stronghold.
The dragon's cave was a stronghold that no one could enter.
The old house was a stronghold for all the cats in the neighborhood.