The Podtrosecká údolí (valleys) comprises several little valleys that form an arch to the north and northeast around Trosky Castle.

The strange ruin of what was once a Gothic castle, founded at the end of the 14th century by the family of Vartenberk, has become the main symbol of the region of Český ráj. 

Vranov Castle, built on the steep rock cliff high above the Jizera River at the beginning of the 15th century, was one of the last castles built in the region.