Canon Elan 7E, handheld Sigma 24-135 at 28mm Ilford HP5 Plus Exposure unrecorded

How high?

Mostly, I like this shot for the composition, and the nice contrasty lines around the edges, followed by the texture. But I also like it for the abstract quality of it, and the fact that it makes it very difficult to produce any scale at all from it. I'd have plenty of people believing this was taken from an airplane until they finally found the seagull tracks at the bottom edge of this tidal pool...