Distance Shadowing?

Sooo I’m finally making my first game (yay!) and currently getting the backdrop put in.

Question is: How do I make the distance in a certain area darker without blotting out all distance altogether?

I’ve got a cityscape backdrop (not just a skybox - actual models in the background) in the direction behind where the player starts the game, and a carnival in front. I’m wanting the area between the cityscape backdrop and the circus entrance, which is filled with trees, to be difficult to see very deeply into to give the illusion that it’s much farther than it actually is without losing the backdrop of buildings in the distance.

How can I do this? Thanks!

You should just put fog. It is more realistic and can help cover up the unrendered textures.
To do this:
Go to Edit → Render settings → Turn on fog
Also try looking into the ambient light and everything else inside the /render settings. Remember that there is always google