Fix horizon line in Photos (as in iPhotos) I recall that it was possible with iPhoto to rotate an image by a small amount, just a few degrees, to rectify the orientation of an image. This is useful to make sure that pictures taken at, say, the seashore have a truly horizontal horizon.

This feature seems to have disappeared in Photos. Is it available within any other tool on El Capitan? Is it hiding somewhere within Photos?
The edit tools are a little bit hidden, but actually easy to get to, once you know how.  

Choose your photo, double click to see it in single view, then just hit  Return ⏎  &amp; it will switch to edit mode. It's also in the Image Menu.

Rotate is unexpectedly not where to find the control, instead it's under Crop, highlighted on the right in this picture...