A German hotel has apologized for an advertisement promoting a "Kristall-Nacht" spa evening that coincided with the 75th anniversary of one of the best-known anti-Semitic events in Nazi Germany.

The BBC reported that the Kristall Sauna-Wellness Park hotel in Bad Klosterlausnitz, Germany, issued an apology for the online ad, which was widely criticized and parodied on social media in Germany. Der Spiegel reported that the hotel called the promotion "insensitive and extremely inappropriate" on its Facebook page. The wording of the ad was also changed to describe the event as a "Romantisches Vollmondschwimmen," or, "long romantic evening."

The timing of the ad was particularly unfortunate as the event was scheduled for November 9, which happens to be the 75th anniversary of the so-called "Night of Broken Glass," commonly called "Kristallnacht," in which Jewish-owned homes and businesses, as well as synagogues, were attacked by Nazis in cities across Germany.

At least 91 Jews were killed in the Kristallnacht pogrom and tens of thousands were arrested in what many historians consider to be the first wave of organized violence against Jews in Hitler's Germany.

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