A former Nazi bunker in Hamburg, built by forced laborers to shelter tens of thousands of Germans during Allied air raids in World War II, will soon house hotel guests.

The 136-room nhow Hamburg, which is being designed by the NH Hotel Group, will open in mid-2021 on top of the Bunker St. Pauli, one of thousands of air raid shelters built across the country by the Third Reich.

The hotel will be part of a five-story tiered garden atop the bunker.

Developers and project managers for the hotel could not be reached for comment, but a spokeswoman for the Spanish hotel chain, Juliane Voss, said they were “aware of the history of the building” and wanted to show “responsibility” for it.

“We understand it’s a sensitive topic,” Ms. Voss said, adding that there were plans for a memorial on the site. “We would like to send a positive signal to the city of Hamburg.”