UTRECHT UNIVERSITY BOTANIC Gardens have one of the biggest rock gardens in Europe. That is bit peculiar, maybe: Utrecht is at about 3 feet (1 m) elevation, and the Netherlands have hardly any natural rock. However, according to photographs, the old botanic gardens in the historical city center had a rock garden as early as 1900. These rock gardens were small, but enough to show biology students the adaptations of high alpine plants to their harsh natural environments. Later on, when the Botanic Gardens obtained an English landscape park in the nearby village of Baarn, a bigger rock garden was built. No natural rock was used for building this rockery: it was built with slag, the waste product of steel production.