Within the series Nature Protection Ceska Posta issued a set of stamps featuring the Karlstejn National Nature Reserve.
The Karlstejn National Nature Reserve (1,547 ha) was established in 1955. The prevailing geological profile consists of limestone rocks with jagged karst canyons, ravines and numerous caves. The area was first populated as early as 40 thousand years ago. The thermophilic plants growing in the reserve are typical of the Mediterranean regions. Some local species, such as the pyramidal orchid (Anacamptis pyramidalis), the Austrian dragonhead (Dracocephalum austriacum), and rare orchid species, are unique and cannot be found anywhere else in Bohemia. Local animals include numerous rare species, such as over 200 species of carabid beetles; two amphibians, the great crested newt (Triturus cristatus) and the less frequent Alpine newt (Triturus alpestris); and the endangered wallcreeper (Tichodroma muraria) as a representative of birds.
The area boasts many precious, geologically significant profiles and world-famous fossil deposits shared with the neighbouring Bohemian Karst area. The prevailing sedimentary structures contain numerous karst caves. The Koneprusy Caves, hidden in the Zlaty kun (Golden Horse) hill about 5 km far from Beroun, are the best known ones. Visitors can see about 600 meters of the more than 2 kilometre long caves. Inside, archaeologists found many animal bones dating back more than half a million years and human bones about 13 thousand years old. A 15th century counterfeiter's workshop was discovered on the upper level of the caves. The greatest tourist attraction is the medieval castle Karlstejn, also known as Karluv Tyn. On the Czech and Roman King Charles IV's order, the foundation stone was laid by the Prague Archbishop Arnost of Pardubice himself in 1348 on the hill later named "Knezi hora" or "Priest's Hill". The originally private residence of the king with its outbuildings was gradually changed into a fortified castle used to safeguard the Czech and imperial crown jewels. The castle's main buildings include the 80 m high "Well Tower" (Studnicni vez); the frequently rebuilt "Burgrave House" (Purkrabstvi); the "Imperial Palace" (Cisarsky palac) with its audience chamber and state rooms; the "Marian Tower" (Marianska vez) with the Church of the Virgin Mary; and the highest "Big Tower" (Velka vez) with the Chapel of the Holy Cross, the former safe place for the Imperial and later also Czech crown jewels kept there until 1619.
The subjects depicted of the stamps:
a. Dracocephalum austriacum and Chorthippus vagans - CZK 10
b. Oenanthe oenanthe - CZK 14
c. Polyommatus coridon, Colias crocea and Pulsatilla pratensis - CZK 18
d. Karlstejn castle and Rosa gallica