Ms. Ghadamian said she heard about the Promontory after visiting a friend who had leukemia and soon died. “I thought, ‘I’m having such a hard time, and I have a support system with family and friends,’” she said. “I thought, ‘How hard it is to be in New York and not have that, not have a place someone could go.’”

The Hallett sanctuary was supposed to be such a place, but, she said, “Everything was so overgrown.” Now, with new pathways and benches, she said, “It’s exactly how I think Frederick Olmsted wanted it.”

Olmsted, of course, was, with Calvert Vaux, a designer of the park, and to Ms. Ghadamian he was an inspiring figure, not only for the park, but also for his other accomplishments, including his work on the United States Sanitary Commission, whose mission was to improve sanitation in the Union Army’s camps during the Civil War and thus the health of its soldiers.