The imposing main walls and their four towers of Yverdon-les-Bains castle follow the geometric characteristics used for lowland castles. It was planned out between 1260-1270 by the young mason and architect James of St. George. He would later travel to England where he would become the master castle builder for King Edward I. James would be responsible for building a series of castles (known as the 'Iron Ring') in North Wales following its conquest by the English Crown.
Yverdon's castle used to be the residence of the castellans of the Savoy dynasty, until 1536, followed by the bailiffs of Bern state. In 1798, the Département du Léman became the castle's owner. The Département had been set up by the short-lived Helvetic Republic (1798–1803), imposed by Napoleon I.
A few years later, Yverdon acquired the castle, to entrust it to Johann Heinrich Pestalozzi and his institute. After 1838, the castle housed a public school. New classrooms were created, especially on the second floor: dividing walls were erected, additional windows changed the severe look of the castle's façade. After 1950, these classrooms were gradually abandoned; the last classes left in 1974. The original medieval structure was then restored. The castle is today a multi-purpose cultural centre, housing a regional museum, a theatre, various conference rooms and the oldest public library of French-speaking Switzerland, founded already in 1763. The library is now part of the castle museum, existing since 1830.References:
Varberg Fortress was built in 1287-1300 by count Jacob Nielsen as protection against his Danish king, who had declared him an outlaw after the murder of King Eric V of Denmark. Jacob had close connections with king Eric II of Norway and as a result got substantial Norwegian assistance with the construction. The fortress, as well as half the county, became Norwegian in 1305.
King Eric's grand daughter, Ingeborg Håkansdotter, inherited the area from her father, King Haakon V of Norway. She and her husband, Eric, Duke of Södermanland, established a semi-independent state out of their Norwegian, Swedish and Danish counties until the death of Erik. They spent considerable time at the fortress. Their son, King Magnus IV of Sweden (Magnus VII of Norway), spent much time at the fortress as well.
The fortress was augmented during the late 16th and early 17th century on order by King Christian IV of Denmark. However, after the Treaty of Brömsebro in 1645 the fortress became Swedish. It was used as a military installation until 1830 and as a prison from the end of the 17th Century until 1931.
It is currently used as a museum and bed and breakfast as well as private accommodation. The moat of the fortress is said to be inhabited by a small lake monster. In August 2006, a couple of witnesses claimed to have seen the monster emerge from the dark water and devour a duck. The creature is described as brown, hairless and with a 40 cm long tail.