What to do with open fireplace/Chimney

[Zach Fulton]

Hey all, I just finished up my first renovation and have it rented out. There's just one thing left that I need to do. I don't know what to do with the fireplace/chimney. I don't believe it is usable and the chimney does not have a crown/cap. A cap would be easy to install, but a crown not so much. Is there a simple way I can cover the chimney up so rain/moisture doesn't get in but also allow proper ventilation? Im not willing to pay the extra money to have the fireplace usable and in good condition. Let me know what you all have done, thanks!