The site known as Tři Křížky (Three Crosses) was named after three crosses that had been erected here in 1859. Three bases with one wooden and two stone crosses stand at the top, with illegible inscriptions in German. Right next to them, there is a plaque made of polished serpentinite showing the direction to significant elevated landmarks (i.e. Vladař, Klínovec etc.). According to legend, the crosses were erected to acknowledge the miraculously healed three brothers suffering from a serious illness, unfortunately, further details remain unknown. A cemetery had allegedly been located on the other side below the crosses.
The whole area of Krásenská vrchovina (Krásno Highlands) is a part of the territory formed by dark metamorphic rock known as HADEC, Křížky information boardin Czech and internationally as SERPENTINITE. The serpentinite area is the largest of its kind in Bohemia and it includes other nature monuments of Slavkovský les (Slavkov Forest): e.g. Pluhův bor (Pluha’s Pine Wood), Dominova skalka (Domina’s Rock Cliff) and Vlček. These habitats have been declared national nature monuments, in particular for being the home of rare plant species, namely the mouse-ear chickweed (Cerastium alsinifolium). Just as a few other localities, the Three Crosses National Nature Monument is distinguished by quite special flora. The parent rock (serpentinite) releases large quantities of magnesium into the soil. Only plants that are able to endure such an environment may grow here. Some have even adapted to such environmental conditions and they cannot be found elsewhere. Some plants grow in dwarf forms (nanism). TheSerpentine with heath winter heath (Erica carnea) is frequent in the Three Crosses. In early spring, blossoming winter heaths cover the surrounding landscape with a claret-red carpet.
Three Crosses were declared a national nature monument in 1962. In 1979, a nature trail was opened on the site and it has been an object of dispute among botanists ever since. Within the framework of ongoing research and reduction of further devastation of the unique habitat, the nature trail was closed in 2001 – the main reason being its alleged renovation – and since then, entry has been prohibited. It is a great pity because the Three Crosses offer a breathtaking view of the countryside. The nature tail was closed, the site was fenced and two information boards were installed by the road (one dedicated to the Three Crosses and the other to the adjacent Globeflower Meadow). The nature monument is under the diligent care of the Slavkovský les PLA Administration.