She also worked on the Princeton and Yale campuses, but many consider Dumbarton Oaks to be her seminal work.

"If Frederick Law Olmstead is the father of landscape architecture, Beatrix Farrand is the mother," Rowe says.

Keenan, says he agrees that the garden must be preserved as a place that is "simply beautiful." But he says focusing on the garden simply because it was created by Farrand, can create a undesirable impulse to freeze the site in time.

"There are all sorts of places where famous people have trodden, but you can't make all of these places into Jerusalem," Keenan says.

Some people adopt a "quasi-religious attitude, which makes us forget that Dumbarton Oaks is a living changing place," Keenan says.

Both Urban and Williams, the team that Harvard has hired to design the library, say that they are completely aware of the need to protect the Dumbarton Oaks garden intact.

Indeed, at the urgings of the D.C. community boards who have reviewed their work so far, the architects have made plans to add a 'cultural landscape historian' to their team.