Sonnevborgh Observatory

The Sonnenborgh bastion was worked in the sixteenth century by request of Emperor Charles V, since he needed to guard the city of Utrecht against another weapon: the portable gun.

The city dividers were subsequently fortified with four bastions, of which Sonnenborgh is the special case that has remained totally in place.

In 1851 the notable physicist Buys Ballot thought of the plan to fabricate an observatory and a meteorological establishment over Sonnenborgh.

The college concurred and Sonnenborgh turned into an observatory and in 1854 the Royal Dutch Meteorological Institute KNMI was established.