An Odd Number of Vaults, and a Museum That Preserved by Accident

The Altneuschul's roof was built with an odd number of vaults, a design choice some accounts tie to a specific religious discomfort rather than to structural necessity.

An unusual ceiling

Built around 1270 in an early Gothic style, the synagogue's main hall is covered by five vaults rather than the four that a square hall of its proportions would ordinarily call for, since a four-vault design would have produced a cross shape overhead, a form some interpretations suggest the builders wished to avoid inside a Jewish house of worship. Whether this was the actual reason or a later explanation attached to an already unusual structure is not confirmed by any surviving building record.

The oldest still functioning

The Altneuschul is widely cited as the oldest active synagogue in Europe still used for regular worship, having survived fires, sieges and repeated periods of persecution against Prague's Jewish community across more than seven centuries without falling permanently out of use.

Preserved by the people who wanted to erase the community

During the Nazi occupation, Prague's synagogues and Jewish ceremonial objects were deliberately catalogued and preserved rather than destroyed, reportedly intended for a planned museum documenting what the occupiers expected to be an extinguished people, an intention that inadvertently left much of the city's Jewish architectural and ritual heritage physically intact when other communities' material culture across occupied Europe was destroyed.