Chlum-Kozlov

Kozlov Castle, also known as Chlum, is a ruined rock castle in the cadastral territory of the village of Olešnice, in the Semily district, standing on Kozlov hill within the Bohemian Paradise (Český ráj) region. The site sits on the northwestern edge of the Hruboskalsko plateau, roughly 2.5 km southwest of Turnov, and counts among the classic rock castles that were built directly into the local sandstone cliffs rather than beside them.

How to get there

The ruins are freely accessible year-round, with no admission fee. A yellow-marked hiking trail connects the Příšovice railway station with Valdštejn Castle and passes directly by Kozlov, making it easy to combine a visit with a longer walk through the sandstone rock formations the region is famous for. Thanks to its proximity to Turnov, the site is a popular stop for day hikers and cyclists exploring Bohemian Paradise.

A brief history

The original castle was built in the 13th century on a sandstone ridge divided into several rock blocks, and its structures were predominantly made of wood, with stone limited mainly to sections carved directly into the rock itself. The first written record of the stronghold dates to 1362 and names Hynek of Lomnice as its owner — a member of a family descending from Jaroslav of Turnov, who lived in the mid-13th century and is considered an ancestor of the Wallenstein (Valdštejn) family. The castle therefore stood within the sphere of influence of this powerful lineage, whose name remains closely tied to the region to this day.

What happened to the castle afterward is poorly documented. It is generally assumed that it lost its importance and gradually fell into ruin once the surrounding estate was attached to the nearby, more powerful Valdštejn Castle, one of the region's key centers of power. No precise information survives, however, about the exact circumstances of its abandonment or possible destruction, so much of its later history has to be pieced together from the scant surviving sources and from the layout of the site itself.

What survives today

Nothing remains of the original wooden buildings — typical for rock castles, whose timber elements decayed and disappeared over the centuries. What has survived are the features carved directly into the sandstone: chambers hollowed out of the rock, traces of the former gateway, a well, and cellars. Remnants of a defensive ditch are also visible, which once separated the castle from the rest of the rock ridge and made approach more difficult for potential attackers. A timber residential and defensive structure once rose above these rock-cut spaces, but no trace of it remains today — only the rock skeleton survives, still giving a sense of how the stronghold was once laid out.

The site's character — once an extensive complex spread across several rock blocks — still makes it possible to appreciate how skillfully medieval builders exploited the natural terrain of Bohemian Paradise for defensive purposes.

Who should visit

Kozlov (Chlum) Castle is best suited to hikers and regional-history enthusiasts who appreciate quieter, less crowded ruins set within nature. It makes a good complement to a visit to the better-known sites of Bohemian Paradise, such as Valdštejn Castle or the region's famous rock towns.

Frequently asked questions

Where exactly is Kozlov Castle located? On Kozlov hill within the cadastral territory of the village of Olešnice, in the Semily district, on the northwestern edge of the Hruboskalsko plateau, about 2.5 km from Turnov.

When was the castle built? Construction dates to the 13th century, and the first written mention of it appears in 1362.

Who owned the castle? In 1362, the owner was Hynek of Lomnice, a member of a family descending from Jaroslav of Turnov, an ancestor of the Wallenstein family.

What has survived from the original stronghold? Rock-cut chambers, traces of the gateway, a well, cellars, and remnants of the defensive ditch — the timber structures have not survived.

Is there an entrance fee? No, the ruins are freely accessible via the yellow-marked hiking trail, with no admission charge.