The 9/11 Memorial Museum is set to open on May 21st and admission will be waived that day due to a grant from Conde Nast.

The 9/11 Memorial Museum will be open to the public on May 21st, but families of 9/11 victims and first responders will get their own chance to preview the museum up to six days before it opens. The six-days known at the Dedication Period will be reserved for 9/11 families, 9/11 rescue and recovery workers, active duty first responders from agencies that lost members in the 2001 attacks, 9/11 survivors, and lower Manhattan residents and business owners. Those attending the preview will have free admission, but will have to make a reservation, the NY Daily News reports.

However when the museum opens on May 21st, admission will also be free for the public that day. Conde Nast, which will be moving to the World Trade Center site, made a donation so that the public can see the museum for free that day, the NY Post reports. However guests must also make reservations. Reservations can be made online at 911memorial.org.

Regular admission will be $24 and the museum will be open from 9 a.m. to 8 p.m. daily. Admission will be free on Tuesdays from 5p.m. to 8 p.m. There will also be discounts for seniors, students and children. Admission to the memorial, which contains two reflection pools, will remain free.

The museum is located at the site of the original World Trade Center and will pay tribute to the 2,983 people killed in the September 11, 2001 attacks and in the February 26, 1993 bombing of the World Trade Center. Another exhibit contains personal artifacts, photographs, audio and video footage and first-person testimonials.