This! 

Nice photo and interesting scenery but so what?
1. The horizon looks higher than what's supposed to be as described in other approaches.
2. I'm considering to be a tourism salesman in case phewtetic is wrong 
Where should the horizon be - in the middle?


There's the horizon in the middle of a nice wide panorama!
But really, the position of the horizon in a photo depends on whether the camera is tilted a little or down, as in your case.
In your photo the camera was tilted down to fit the small bay and natural bridge in.
And the position of the horizon in a photo relative to other objects depends on the height of those objects relative to the camera.
But you'd better get to that tourism salesmen's course and in addition one on photography would help because tourism salesmen might need to take excellent photos of the highlights.