Since the royal family resided in forts, it had many features serving the purpose of security of the inmates.
1. High and thick walls of forts made sure it was difficult for people trying to cross it by breaking them down or simply jumping over them.
2. Doors had metal spikes on them which hurt enemy soldiers or elephants trying to barge them down.
3. Several bastions of the forts enabled soldiers in the fort to always have an eye on enemy soldiers approaching the fort in all possible directions. Bastions also helped soldiers to launch attack on the enemy soldiers without giving a clue.