Ore Mountain passes
The Ore Mountain passes () are crossings and passages over the crest of the Ore Mountains in Central Europe, over which tracks, roads, railway lines and pipelines run from the Free State of Saxony in the Federal Republic of Germany to Bohemia in the Czech Republic and vice versa. Upper Ore Mountains from a transport perspective. The shape of the terrain and the climate are the most important physical-geographic conditions that exert an influence on the course and the design of routes across the Ore Mountains, even today. Geomorphologically, the mountains form a fault block, sharply uplifted  in the south and sloping gradually away to the north. The appearance of the mountains in the Saxon part is characterised less by their absolute height, but by deep and sometimes winding valleys that have cut notches up to 200 metres deep into the terrain. The area between the valleys comprises gently rolling plateaus that from an early time enabled favourable transportation routes to be developed, often with gentle inclines. In fact such communications only became a problem where one of the deep valleys had to be crossed. Significantly less easy to negotiate, however, is the steep descent to the  south towards Bohemia, where the Ore Mountains drop up to 700 metres in less than 10 kilometres. Even today, the upgraded transit roads in this section have gradients of over 10%. The Ore Mountain crest itself forms a series of plateaus and individual peaks, interrupted by saddles. From the Vogtland the ridge climbs to about 1,000 metres in height and then falls to about 900 metres near Johanngeorgenstadt (Platten Pass). The ridge rises again to the Fichtelberg/Klínovec (Keilberg) summits that are over 1,200 metres high. Between the two mountains, the crest sinks down to the Wiesenthal Pass at 1,080  metres. By Deutscheinsiedler Saddle, the lowest crossing over the mountains, the ridgeline drops by 750 metres to the Reitzenhain Pass (820 m). To the north-east the crest reaches 900 metres again at the Kahleberg before descending to about 500 metres to the Elbe Sandstone Mountains. Due to the lack of a water gap through the mountains, the mountain passes are relatively high. Thus, the middle ridge of the Ore Mountains is about 880 metres high and the average saddle height is only slightly lower at 810 metres. Because the fault block is uplifted on one side along the Eger  trough and the border diverges away from the ridge line, the Ore Mountains reach their greatest height on the Bohemian side. Thus most of the passes are already in Bohemia. They reach an average altitude of 700–900 m above sea level. The highest pass, at 1,083 m above sea level, is the Wiesenthal Pass. The lowest-lying is the Nollendorf Pass at 680 m. On the upper slopes of the Ore Mountains the climate may quite clearly be described as harsh. For that reason, the Upper Ore Mountains was also referred to in the past as Saxon Siberia. The annual  rainfall on the high ridges is up to over 1,100 millimetres, with the majority falling as snow. The annual average temperatures reach values of only 3 to 5 °C. At Oberwiesenthal, located 922 m above sea level, there are on average only about 140 frost-free days a year. These winter temperatures and snowfalls during the winter months, especially on the mountain passes, lead to traffic problems, congestion and closures, even today. According to reports by historians in the past, winters in previous centuries in the upper Ore Mountain regions must have been even harder than today. Prolonged periods  of frost and continuous snow cover, metre-high snowdrifts and snow storms often made roads and passes impassable for weeks. Reports by the State Post Office on the road to the mining town of Sayda on the Deutscheinsiedler Saddle dated February 1855, state that ""... because of the immense masses of snow, progress [is] almost impossible, just as impossible are the conditions during snowfalls"". Post had to be transported by sledge and messengers, "because "two horses side by side cannot not wade through the piles of snow"". Mention should also be made of the danger of flooding during the snow  melts in summer and thunderstorms. Floods have occurred repeatedly in the past, most recently in August 2002, when considerable destruction was caused to access roads in the valleys to the Ore Mountain passes. Nakléřov Pass. One route variation of the Kulmer Steig ran over the Nakléřov Pass in the eastern Ore Mountains. The old road crossed the Saxon-Bohemian border from Fürstenwalde in the west to Oelsen in the east and ran down the steep escarpment of the Ore Mountains into the Bohemian Chlumec u Chabařovic and on into the interior of the Kingdom of Bohemia. The Kulmer Steig was  reportedly being used in the 13th century. The pass became known as a result of the War of the Sixth Coalition and the Battle of Kulm and Nollendorf on 29 and 30 August 1813. In Berlin-Schöneberg, "Nollendorfplatz" and "Nollendorfstraße" are named after the small Ore Mountain village of Nakléřov (Nollendorf), of which nothing is left today of the church town that according to legend Napoleon watched the battle from. From 1913 to just after 1950 a 21 metre high observation tower stood on the Nakléřovská výšina, which bore the name "Kaiserwarte" and, after 1919, "Carl Weis Warte". The Nakléřov  Pass has in recent history been the subject of both positive and negative headlines. In 1936 the Olympic Flame crossed the pass on its way from Athens to Berlin. A monument erected on the border at Bahratal recalls this. In 1968 the Red Army used the mountain crossing in order to suppress the Prague Spring reforms by invading Czechoslovakia.