Natural spectacle in Bavaria: the pond shimmers purple - a phenomenon that only happens every few years. An expert explains why the pond in Füssen suddenly glows purple.
In order for the bacteria to appear, the water must contain little oxygen and sulfur. Factors such as temperature, wind and light influence the discoloration. No one would go swimming in the pond because it is not bathing season and the water smells of sulfur. It is impossible to predict how long this natural spectacle will last.