Orlické hory has been declared a Protected Landscape Region since 28 December 1969. PLA Orlické hory contains 19 small specially protected areas 415 ha in total size.
The entire mountain range edges the Bohemian basin, creating a natural border. Orlické hory rise up on the north-east edge of Bohemia, marked by a stretched-out, over 50 km long, ridge at an elevation of around 1000 m a.s.l.
Orlické hory are formed from rocks (shale, conglomerates, sandstone) which were produced from the sediments of a Precambrian sea. All the upper sections of the mountain chain have been eroded away by water with only parts which got trapped in deep sections and were transformed through high temperature being preserved. This type of rock is known as schist. Orlické hory are formed from this schist rock, alongside igneous intrusions.
Orlické hory are divided into three sections (Deštenská hornatina, Mladkovská hornatina and Bukohorská hornatina), with Velká Deštná its highest peak at an elevation of 1 115 m a.s.l.
Almost all ridges run north-east – south-east and have a major impact on the climate. Westerly winds are prevalent in Orlické hory, with average annual temperatures of around 5 °C.