Máxima commemorated one of her nation's most tragic stories, visiting a New York show that recreates the annex where the Frank family hid from Nazis.

The queen honored one of her nation's most tragic stories, visiting a New York show that recreates the annex where Anne Frank hid from the Nazis.

"I was afraid I'd have to curtsy or do something, and she's very approachable and very nice," Leo Ullman tells PEOPLE about meeting the Dutch Queen

Miep Gies opened the “secret annex” in her employer’s office building where Nazis had just arrested her boss, Otto Frank, who was hiding there with his family — wife Edith and daughters Margot and Anne.