How do l re-download Babylon?

Hello. I have an issue ovah here. I have bought all content for Civ V, including Babylon. The problem is that l cant see Babylon ingame & it says l have not downloaded it. I have been able to play Babylon before, so l cant see what has happened. I have not added any mods whatsoever. I also dont know where to download it once more. Can someone help?
Thank you :3

Firstly, I think you meant to make this post in the Civ5 forum rather than the BE one.

But with regard to your question: right click Civilization 5 in your Steam library, open up properties, and go to the DLC tab. Is the Babylon DLC checked? If not, then it will automatically download after you check it.

Otherwise, try validating your game cache, if Babylon somehow got corrupted then it will re-download all the broken files and Babylons hould correctly show up.