Gnomonic Blocks, or Multi-faceted Sundials

In the park of the Abbey of Epau, in Yvré-l'Evêque in France, you can admire a curious monument in the shape of an obelisk. Built by the Benedictine monk Bedos de Celles between 1631 and 1640, the sculpture consists of four sides, perfectly symmetrical, and oriented along the cardinal directions, with several curious protrusions and shapes. Each of these shapes has a purpose: they are sundials, a total of thirty in all.

Sundial of the Groirie in Yvré-l'Evêque.