Help with Panama Canal

[Stagnetti]

I wanted to build the Panama Canal this game, because it would be fun, and it would connect the lake to the south east to the ocean. The game says I cannot place it down and I can't figure out why.
https://i.imgur.com/Q6RLmS8.jpeg
See in the screenshot above, the game says there is no suitable location to construct this. The yellow tile is where I should be able to place it considering:
- The tile is flat land
- The tile is owned by Gelonus
- The two green tiles are directly across from the wonder tile
- They are both legal canal tiles (the north tile has a 60 degree bend) (I think?)
- I know that Gelonus does not own the southern tile, but before I captured the city to the south east, Gelonus did own that tile, but it still would not let me place it. Of course, I can't swap it back in now because it's more than 3 tiles away

So my only thought is that the connecting canal tiles need to be within 3 tiles of the city that's constructing the wonder, any other ideas?

[jmerry82]

The northern tile looks to be a mine on a grassland hill. Canals must be placed on flat land.

[Stagnetti]

Originally posted by jmerry82:

The northern tile looks to be a mine on a grassland hill. Canals must be placed on flat land.

Oh, right, I've gotten myself mixed up over the course of the game. I think originally I was thinking the tile to the east of that, which is flat, but that means that the two canal tiles aren't directly across from eachother. Thanks.