Wikipedia
Brdy are hills in the Czech Republic, forming a long massif stretching for cca.60 km from Prague in the direction of southwest. The northern section of the Brdy is called "Hřebeny" and features one narrow ridge (highest elevation Písek - 690 m.). The Brdy proper starts south of the Litavka river gorge and consists of several major elevations connected into one plateau. The highest being "Tok" (864 m.), "Praha" (862 m.) or "Třemšín" (827 m.).
Most of the Brdy is covered by forest which make it one of the largest contiguously forested areas in the interior of the Czech republic. However, major sections of the massif have been declared closed military area and are largely banned to public.
The military area of Brdy has been a source of controversy for several decades.
The closed military area was declared shortly after emergence of Czechoslovakia to cater for needs of growing Czechoslovak armed forces in 1925. It has been expanded and well used by Third Reich military forces during the Nazi occupation of Czechoslovakia during 1939-1945. It has been further used for intensive military exercises in post war era with some additional expansion in the southern sector.
After the Warsaw Pact intervention in August 1968, southern locality near town Mirosov served as base to a small Red Army contingent until its repatriation in 1993.
Military use of the Brdy mountains gradually decreased after the Velvet Revolution in 1989 driven by military cost cutting and eventual professionalization in 2005. However, the closed military status of the central part persists.
Brdy mountains were in the focus of American negotiators attempting to settle a deal with Czech government to install a Ground-Based Midcourse Defense missile defense radar system in this military area. The plans for missile defense had been reshaped in U.S. President Barack Obama's administration and Brdy had lost most of its strategic importance.