The town was one of the smallest cities in the Hanseatic League, but had become prosperous in the fourteenth and fifteenth century through its trade in beer, hops, linen, and yarn.

In retrospect, this Brunswick period constituted Alfeld's Golden Age, its economy and culture flourishing before the Thirty Years' War.

Sights in Alfeld include the town hall (1586) with its octagonal tower, the church Saint Nicolai and the Fillerturm, a medieval watchtower, and the Fagus Factory of 1911, a fine example of early modernist architecture by Walter Gropius.

More famous are the Seven Hills (German: Sieben Berge) in the north and the Lippoldshöhle ("Lippold's cave"), where a legendary robber-knight is said to have lived.

The biggest employer of the city is the SAPPI (South African Pulp and Paper Industry) factory with its big chimney, which has become one of Alfeld's landmarks.