Biševo – International Dark Sky Park
Measurements of the night sky on the island of Biševo show remarkable values that are very close to the almost completely naturally dark night sky (with the darkest measured value of 21.72 mag/arcsec2 at 21:48, from a location on a hill near the Porat bay). Considering the very small population and the distance from the mainland and other islands, this is expected, but precisely because of this, the importance of preserving such a natural sky for the local ecosystem should be emphasized.
Since there is less and less natural night sky in Croatia, it is of great importance to preserve the quality of the natural night that Biševo has.
The value of the dark sky of the island of Biševo was also recognized by the Zagreb Observatory - the Zagreb Astronomical Association, which in this context supported the initiative to declare the island of Biševo a significant landscape.