Sonnefeld Monastery, dedicated to the Blessed Virgin Mary, was founded in 1260 by Henry II von Sonneberg and his wife Kunigunde. The Monastery was at the beginning in Ebersdorf bei Coburg but, after a great fire in 1267, it was moved to Hofstädten. But the Monastery and its surrounding settlement and district adopted Sonnefeld as their names and kept it until 1889, when Sonnefeld and Hofstädten merged to become Sonnefeld. The landlord at the beginning was the Prince-Bishop of Bamberg, Berthold von Leiningen, who tried to stop the foundation and also the advances of the Counts von Hennebergs. The spiritual leader was the Bishop of Würzburg. The settlement was made by the nuns from the Maidbronn Abbey. It included the nearby villages of Frohnlach and Ebersdorf. In 1262, the Abbots of Ebrach and Bildhausen inspected the progress and provided for the recognition of the Order.
The Monastery's founder Henry II was also among the witnesses of the foundation of the Himmelkron Abbey. The Sonnefeld Monastery was Henneberger. Under Abbess Anna von Henneberg, whose epitaph has been preserved, it flourished. The decline began as early as the 14th Century. The number of nuns had risen beyond the economical limits and had to be restricted to 50 people. The provisions for the maidens and widows of the nobles and commoners soon became the focus of the monastic life. Private property became common, contrary to the rules of the Cistercian Order. But the number of recruits decreased. Under Abbess Margaretha von Brandenstein (ca 1460–1503), the Monastery flourished for the last time, because the Abbess had managed the debts and began several construction projects. In 1504, most of the nuns turned against the Abbess, because they wanted to introduce the Claustration again. The Abbott of the Georgenthal Abbey was employed as a Visitor and detained some of the nuns.
Beginning with the former Bamberger fiefs of Sonnefeld, Frohnlach and Ebersdorf, the Monastery multiplied its possessions with other properties from Bamberg, the Banz Abbey and the Benedictine abbey of Saalfeld. A papal letter of protection of 1291 named 34 localities. The Monastery grew until the end of the Middle Ages as one of the largest landowners in the Coburger Land. It had an almost complete dominion over Weißenbrunn vorm Wald. There were also regular donations from local noble families, especially the Schaumberg family and the Marshals von Kunstadt. Since 1331 the Monastery had the right of residence in a townhouse in Bamberg at Grünen Markt and was the owner of a few houses in Coburg. Through Anna von Henneberg the Monastery also came into the possession of vineyards in Nüdlingen and Nassach.
In 1524 a Lutheran preacher had the nuns to defy the wishes of the last Abbess Margaretha von Zedtwitz by a Lutheran preacher. When the Abbess died a year later, the Council of John, Elector of Saxony appointed an administrator for the Monastery's properties. Five of the 14 nuns left the Monastery in favor of the worldly life, and the last of the remaining nuns died in 1572. The property then fell to the territorial sovereignty of Saxe-Coburg as a district. Anna of Saxony spent several years of her captivity in the former monastery and was buried in the church.
The church was built, according to the style of the Cistercians, next to the choir and nave with an adjacent walk-in vault, above which was the gallery for the nuns. The choir area was the work of Heinrich Parler but its character was partially lost to fires and renovations. Among other things, the roof turret, a Parler trademark, was removed. Only a few gravestones have survived from the monastery's days as the reminders of Abbess Anna von Henneberg and a Schaumberger knight. The Klosterkirche became the parish church for the Protestants in 1520. The previous parish church is the present cemetery church, St. Moritz.
In 1634 the monastery and church burned to the ground. In 1856, they were restored. Of the monastery only a part of the east wing is preserved. A keystone in the arch bears the arms of Abbess Dorothea von Kemmaten (circa 1453). The remains of the paintings from the late 15th century can still be seen.
The entire monastery area consisted of several buildings, which were surrounded by a moat. The buildings, besides the residences, were used mostly for the agriculture and the administration. One of them was operated as the Monastery's mill. The buildings also included a district office, a Fronfeste (fortified bridge) and a school.
The Externsteine (Extern stones) is a distinctive sandstone rock formation located in the Teutoburg Forest, near the town of Horn-Bad Meinberg. The formation is a tor consisting of several tall, narrow columns of rock which rise abruptly from the surrounding wooded hills. Archaeological excavations have yielded some Upper Paleolithic stone tools dating to about 10,700 BC from 9,600 BC.
In a popular tradition going back to an idea proposed to Hermann Hamelmann in 1564, the Externsteine are identified as a sacred site of the pagan Saxons, and the location of the Irminsul (sacral pillar-like object in German paganism) idol reportedly destroyed by Charlemagne; there is however no archaeological evidence that would confirm the site's use during the relevant period.
The stones were used as the site of a hermitage in the Middle Ages, and by at least the high medieval period were the site of a Christian chapel. The Externsteine relief is a medieval depiction of the Descent from the Cross. It remains controversial whether the site was already used for Christian worship in the 8th to early 10th centuries.
The Externsteine gained prominence when Völkisch and nationalistic scholars took an interest in the late 19th and early 20th centuries. This interest peaked under the Nazi regime, when the Externsteine became a focus of nazi propaganda. Today, they remain a popular tourist destination and also continue to attract Neo-Pagans and Neo-Nazis.