This particular region of the Mandelbrot set is near $$-0.5+0.5i$$. The image above is about one ten thousandth of a unit across, while the larger image is about one thousandth of a unit across (give or take a bit). This region sits on the edge of the Mandelbrot set to the ‘north’ (positive imaginary component) of Seahorse Valley. The region contains seahorse-like structures, but they are less clearly defined.