Why can't I place the Ruhr Valley here?

[Sesostris]

I've built up this sweet production city and really looked forward to boosting it with the Ruhr Valley, but now I find that I can't place it where I thought. As far as I can see, the place marked with the blue circle fulfills all the requirements, but I'm not allowed to place the Ruhr Valley there. Can someone please tell me what I'm missing? Does the industrial zone have to be next to the river too?

City view

 

[Sun Tzu Wu]

The tile circled in blue appears to be a Floodplain. Civ VI normally does not allow world wonders to be built on Floodplains.

 

[Sesostris]

Ahh, thank you. Disappointing, but now I at least know why.

 

[Sun Tzu Wu]

You're welcome!