Greetings @Hossein530 !
Welcome to the Unreal Engine community! 
Thank you for sharing your project with us. This is reminiscent of a place with original, long-standing, centuries old, solid architecture. Where Iām from, there are many such cobblestone alleyways with back doors to restaurants and hotels. Employees step into the alley way for a smoke break and a quick huddle. Debris from the alley way is washed away with a water hose down the trench into the drain below.
The lighting at night is spot-on. The light fog really adds to the atmosphere. Was your project inspired by an existing location?