The specific properties of water are at the origin of the landscapes of frozen lakes frequent in winter in Auvergne. Water is in equilibrium in a solid form below 32° F (0° C), its solid form is 10% less dense than its liquid form, and it reaches its maximum density at a temperature of 39.2° F (4° C). All these factors explain why the ice floe floats on the oceans, ice cubes remain on the surface of the glasses of water, or why lakes freeze on their top layer, offering a new space of walk to hikers such as in Lake Servières in the Puy-de-Dôme department.