Tracking the sunrise in Mablethorpe

The structure above is on the seafront at Mablethorpe in Lincolnshire. I thought it was a sundial. It does indeed work by projecting a shadow of the Sun, but it has been set up to record the position of the Sun at sunrise on specific dates throughout the year. So it's like a latter day Stonehenge. The lines on the pavement are labelled with dates.

The line furthest right in the top photograph is labelled "True South". In other words, that is the position of the Sun at midday (allowing for the analemma issue). Summer Solstice is the line nearest to it, and Winter Solstice is the line furthest away. This because on the Summer Solstice, the sun rises the furthest north of any day as it has further to go across the sky to reach south by midday. The Sun is out for more hours on that day. Hence its shadow at sunrise must be closest to the south. It is almost counter-intuitive and it took me a while to understand it.