The Brocken, also sometimes referred to as the Blocksberg, is the highest peak in the Harz mountain range and also the highest peak in Northern Germany; it is near Schierke in the German state of Saxony-Anhalt between the rivers Weser and Elbe. Although its elevation of 1,141 metres (3,743 ft) is below alpine dimensions, its microclimate resembles that of mountains of about 2,000 m (6,600 ft). The peak above the tree line tends to have a snow cover from September to May, and mists and fogs shroud it up to 300 days of the year. The mean annual temperature is only 2.9 °C (37.2 °F). It is the easternmost mountain in northern Germany; travelling east in a straight line, the next prominent elevation would be in the Ural Mountains in Russia.

A Brocken spectre, also called Brocken bow, mountain spectre, or spectre of the Brocken is the magnified shadow of an observer cast in mid air upon any type of cloud opposite a strong light source. The figure's head can be surrounded by a bright area called Heiligenschein, or halo-like rings of rainbow-coloured light forming a glory, which appear opposite the Sun's direction when uniformly sized water droplets in clouds refract and backscatter sunlight.