Shrouded in mystery and beautifully maintained, the 182-year-old Gramercy Park is kept under lock and key. To get behind the gates, one must be approved by Arlene Harrison, who has served as the vanguard for all that is acceptable in the park's lush two acres for three decades. Harrison is the keeper of all the keys. A personal key, which is virtually impossible to duplicate, costs a condo or co-op owner $350. If the key is lost, it costs the owner $1,000 to replace. Each key comes with a chain and a brass plate with the buyer's name on it - for an extra $125. Key holders include Alexander Rower, the grandson of Alexander Calder, and Samuel G. White, the great grandson of Stanford White. Harrison's key is always strapped around her wrist and she has never lost it.

Harrison's formal title is lifetime trustee and head of community for the 2,000-member Gramercy Park Block Association. However, most refer to her simply as "the mayor." She's quick to point out it's not a self-proclaimed title, yet very apropos for the woman often seen wielding her signature clipboard. "I love working every day 5 a.m. to 10 p.m., seven days a week," she says. "At 7 a.m. I walk the park and meet with the park caretaker who arrives at that time. Then I circle around the park greeting and speaking to neighbors, children on their way to school, neighborhood workers, building personnel, and construction workers. People know they can always talk to me about any concerns they may have. There is nothing  I am more passionate about than spending my days caring for my neighbors, our park, and the neighborhood."

Holding these titles is dear to Harrison's heart. In the early '90s, her son was attacked by a wilding gang near the park while returning to the family's townhouse. She has single-handedly spearheaded the initiative to keep the park safe and functional for those lucky enough to gain access. While some view her as a vigilante of sorts, she insists that her role is vital. "We've become fiercely dedicated to preserving and protecting the quality of life and historic nature of Gramercy Park," Harrison says.

While the park's relationship with the nearby Gramercy Park Hotel has been rocky. Harrison remains amicable with the trendy Aby Rosen run property. "I visit Danny Meyer's Maialino Restaurant in the hotel daily, and it's become my 'de facto city hall.' Neighbors know they can find me there in the early morning if they want to discuss the park and neighborhood business. I consider both the Maialino and hotel staff part of our Gramercy Park family."

Teddy Roosevelt and John F. Kennedy are also counted as former members of this family as both played in the park as children. Today, the crowd within the park's confines veers more toward those seeking a private space for jogging or relaxing as well as the sporadic visitor looking to take in some of the onsite art installations. The park's leafy grounds have strict rules: no dogs, no smoking, no wedding-party photo shoots, no bicycling, no hardball, no Frisbees, no feeding the birds or squirrels, no lawn furniture and absolutely no booze. "One 94-year-old lady comes every day, sits on the same bench and completes the NY Times crossword puzzle," Harrison says.

Harrison's intimate knowledge of all of the park's patrons is impressive to say the least, but it's clear that her sphere of influence expands far beyond these boundaries. She keeps her hand in all of the real-estate dealings nearby, including Zeckendorf Development's 18 Gramercy Park. "I initially told Will Zeckendorf that after his and architect Robert A. M. Stern's astounding success at 15 Central Park West, he could purchase any building in the city," she says, "But none would have at two-acre private park as its front yard." 

This article has been edited from its original version.