Made with Mandelbulb3d.
The whole structure is a single layered fractal, very basic post-production. Even the windows are lighted with MB3d.
But the flare and the sky are applied with Photoshop and they hide a little the lighthouse, so I put this in fractal manipulation.
I have no personal pictures of the sea, so I used another of my skies to make the water; they're actually clouds, not waves