Enigma in linea «Monastery»

who is stuck at the point 3?? Many parts of the puzzle do not differ visually, due to the fact that the picture has large areas (a third area and above) painted a solid color without the presence of graphic elements that allows at least approximately to locate them in the puzzle. painted a solid color!!!! and here the sky in the clouds, the ripples on the water!!!!! where completely the color of the third square and above!!!