When all the ice on earth melts, the average level of the sea will be around 200 feet higher than it is now. The Post-it note in the photo marks where a public footpath crosses the 200-foot contour in the Nant yr Efail catchment.
The numbers under the photo are date and Ordnance Survey grid reference in the form: yyyymmdd_easting-northing. The what3words reference follows the numbers.
Back to the ‘When all the ice melts’ blog post.