"Then from my heart will young petals diverge,
As rays of the sun from their focus;
I from the darkness of earth will emerge,
A happy and beautiful crocus."
Hannah Flagg Gould
A rectangular lake! It's an artificial one called Metzgerallmend - as part of sand-mining operations, the mining company can't just leave a big hole in the ground, so they convert the area into a lake so it can at least contribute some outdoor recreational value.
