Town in the Harz Mountains, where in the fall of 1801 Israel Jacobson founded the school which was called after him (See Jacobson, Israel). The institution received large endowments from the founder and his descendants, and from other philanthropists, especially Nathan Beer Isaac, court agent at Brunswick, being thereby enabled to receive a number of free scholars, among whom (from 1805) were many Christians, principally from Seesen. In 1810 the school was organized as an elementary common school. In the same year a temple was built by Jacobson for the institution, and was the first Jewish place of worship into which German sermons, a choral service, and an organ were introduced. The continuously increasing number of pupils necessitated repeated enlargements of the school. In 1886 the curriculum was changed in conformity with the Prussian normal-school plan for Realschulen. The school is under the supervision of the ducal school commission of Brunswick, and is empowered to give certificates for the one-year volunteer military service. The present (1905) director of the school is Dr. Emil Philippson. There are ten classes, with a total of 275 pupils, of whom 123 are Jews and 152 Christians.
In 1852 Jacobson's eldest son, Meyer Jacobson, founded in Seesen an orphan asylum for Jewish and Christian boys. The first building used for its purposes was the original home of the Steinway family of New York, and this was replaced by a large new building in 1902.
The Jews of Seesen number 69 in a total population of 4,729.