Alexandra Graubert is great-niece of Enid A. Haupt. Sylvia Ripley is a daughter of S. Dillon Ripley II.

Smithsonian Secretary S. Dillon Ripley II had a vision: a 19th-century garden to accompany the Smithsonian’s iconic 19th-century Castle. Hidden under the garden were two museums and a study center where education could take place at the Smithsonian. Ripley made friends with Enid Annenberg Haupt, a lady who loved gardens and who was inspired to become a donor. The Enid A. Haupt Garden was installed over the S. Dillon Ripley Center.

Ripley died in 2001. Haupt died in 2005. By 2012, the Smithsonian Institution began its plan to destroy the garden and the study center.

Widespread public alarm resulted in the unanimous vote of the D.C. Historic Preservation Review Board on April 27, 2017, to designate the Haupt Garden and surrounding area as a historic district in the D.C. Inventory of Historic Sites. As family to Ripley and Haupt, we supported this designation. Unfortunately, the Smithsonian is pressing ahead with plans by architectural firm Bjarke Ingels Group to make changes costing $2 billion.

We urge the leadership of the Smithsonian to leave the garden design intact, and in so doing not only respect the expert assessment by the Historic Preservation Review Board but also honor in good faith the commitments made to Enid Annenberg Haupt when funds for the garden’s construction and maintenance in perpetuity were solicited from her.

We also beg respect and preservation for the entrance to the Ripley Center. Misidentified as a “kiosk” in the Smithsonian’s plans, it is actually a charming chinoiserie garden folly, such as was often placed in 19th-century gardens. Catching sight of it entices pedestrians from the Mall to the garden and reveals the entrance to the Ripley Center, an underground conference center used by the scientific community and the general public. It commemorates one of the greatest secretaries of the Smithsonian. The Smithsonian wants to tear it down to accommodate a larger loading dock for big trucks.

Ripley added eight museums at the Smithsonian, an expansion made possible in large part by his ability to attract private donors. Private donors remain critically important to the success of the Smithsonian. We want to preserve the Smithsonian’s reputation for soliciting funds in good faith and conscientiously carrying out the intentions of the donors. More money will need to be raised if any substantial part of the new plan goes forward. Future donors should rightly be wary of contributing to a project that betrays promises to previous donors. How will the Smithsonian be able to ask for endowments after this?

The Smithsonian’s study shows that the museums in this area are the least visited of all their museums. The two landmarked Jean Paul Carlhian-designed pavilions attract fewer visitors because the museums’ collections are highly specialized, not because their entrances were wrongly placed. The new entrances — glass boxes placed directly next to the Castle — will destroy the visitor’s experience of leaving the 19th-century Castle to enter the 19th-century-inspired Haupt Garden. Described as transparent, the glass boxes quickly will become filthy — sticky with tree sap and dingy gray with diesel exhaust. (An example of the failure of this design gambit can be seen in the glass elevator boxes in front of Washington National Cathedral.)

The Smithsonian can achieve its aim with existing resources. The Castle serves as a visitor center and is flexible enough for further changes. The Arts and Industries Building offers an enormous space for special events. The Ripley Center already exists as a conference center, one of the supposed advantages of the new visitor center. The Carlhian pavilions function as they were meant to: They enclose the space and aesthetically link the surrounding buildings, while offering a welcoming entry to visitors coming from the southwest.

The new plan shows a futuristic visitor center, to be placed beneath the garden. In concept it appears to be modeled after the iconic I.M. Pei visitor center and entrance at the Louvre. However, the Louvre is a giant royal palace-turned-museum, where thousands of people line up daily to buy tickets. The Smithsonian is a scattered set of buildings to which admission is free.

The Smithsonian’s desire for a Bjarke Ingels Group-designed project should be satisfied elsewhere on other land — not land that has been landmarked. Sited elsewhere, the Bjarke Ingels Group concept may be a true monument to our time. But please not in the Haupt Garden.