The Královéhradecký kraj (Hradec Králové Region) is named after its capital Hradec Králové. This is the northeastern Bohemia bordering Poland and Silesia.
Most of the area is lowlands with some sandstone ridges which are called Broumovská vrchovina (Braunauer Bergland). The rocks are mostly sandstones from the middle and upper Turonian and Coniac, which are subunits of the Cretaceous. The show typical differential erosion and form towers, mushrooms and gorges. The gorges are not the result of rivers, they are created by weathering along cracks. Such sandstone ridges extend from the Dresden area in Germany through northern Bohemia to southern Poland.
The area has no notable karst areas but there are some patches of limestones. Several caves exist in the area, one is even 500 m long, but there is no show cave and no other cave open to the public. Nevertheless, the area has a unique cave named Poseidon with a total length of 19,655 m. The cave is located in sandstone and of erosional and tectonic origin, and is the longest sandstone cave of the world. Small parts are accessible on the walking trails through the Teplice part of the Adršpašsko-teplické skály.