For all the world it looks like this was a cobbled pavement laid down by a gang of workers, but this is a limestone pavement on Llantwit beach.
It was later in the day so, in order to get the sea to have that silky look, I brought out the 10 stop ND filter to allow me to slow down my shutter speed. 25 seconds was sufficient in this case.
I was also shooting towards the sun – giving this washed out monochrome look. i like it.
Photography stuff: 12-24mm lens at 12mm, 25 seconds at f/8.0, 2 stop hard graduated ND filter to hold back the sky, 10 stop ND filter to allow long exposure, tripod.