Sean Cole is a poet and he knows what you think of that. He is also a radio producer. One night, drunk and stumbling around the Hudson River with his friend Malissa O’Donnell, he discovered a monument — two of them actually — to two of his poetry heroes. Apropos of the name of this show, the tribute wasn’t very obvious. In fact, he and Malissa nearly walked right past it. Still, embedded in the architecture of a 25 year old plaza were the words of Walt Whitman and Frank O’Hara. And weirdly, Sean had he’d been reciting from O’Hara’s Lunch Poems just minutes before. Thus began Sean’s quest to talk to the people whose idea this was — forging a largely unloved art form into a permanent fixture of the cultural landscape. Along the way he talks with urban landscape architect M. Paul Friedberg, former Battery Park official Richard Kahan and none other than Frank O’Hara’s younger sister, Maureen O’Hara. Sean Cole and Malissa O’Donnell both work for WNYC’s Radiolab. And Sean is also a 99-percentilist from way back.