Passage to the fortress

The entrance to the fortress is curved at a right angle so that the Citadel cannot be taken by a dashing cavalry attack. Additionally, there is a sinkhole trap in the passage, in the picture it is covered with boards. To the left is a copper-clad gate is seen. Well, as is customary in our Palestines - a metal detector at the entrance, a police checkpoint and all of that... What can we do, the country is surrounded by enemies...