A Dutch Jewish organization rediscovered two ritual baths that had been forgotten after the Holocaust.

In reporting about the find Friday, the Crescas Jewish education institute wrote on its website that large parts of the 19th-century ritual baths, or mikvehs, were unearthed last week at a Jewish community building in the northern city of Groningen.

“The mikvehs are an exciting find,” Crescas wrote. “They are remarkably well-preserved. The marble of one of the baths was partially damaged during renovations.”

The mikvehs, which are seven-feet deep, have seven marble stairs, according to Crescas.

The Jewish community of Groningen, which was nearly wiped out during the Holocaust, sold the building in 1952 to the municipality, which renovated the building and rededicated it as a seat of the Jewish community in 1981. The mikvehs were covered up and exposed only recently, after members of the local Jewish community chanced upon blueprints of the building, the RTV Noord television station reported.

“The find is so important because Jewish life stopped here in 1943: the Jews were gone. A few buildings that were essential to the Jewish community remained: the synagogue, the old people’s home, the Jewish school, but the mikveh, which is also essential, was gone. No one knew where it was,” Marcel Wichgers, director of Groningen’s Folkingestraat Synagogue Association, or SFS, told RTV.

SFS was unaware until recently that the two mikvehs lay under the floor of a room it used for storage, Crescas wrote.

The Reformatorisch Dagblad daily described the find as one of the most important archeological discoveries made in Groningen in recent years. The structure is now opened to spectators twice a week, on Wednesdays and Sundays.

In 1930, the Jewish population in Groningen was 2,408, according to the Amsterdam’s Jewish Historical Museum. In 1951, there were 225 Jews, and currently only a few dozen Jews live in the northern city.