Roxy Paine in Madison Square Park

The revitalization of Madison Square Park has to be one of the city's great success stories of the aught years, transforming this six-acre plot from a decrepit haven for junkies and thugs to a vibrant, grassy public space that's packed everyday at lunchtime (thanks in part to the ridiculously popular Shake Shack), and that provides a comfortable venue from which to view such landmarks as the beautiful Flatiron building, the slightly silly Eleven Madison Avenue (designed to be 100 stories tall, they stopped construction on floor 29 when the Great Depression hit... so it's all base, no finish), and the Metropolitan Life building (a century ago, the tallest in the world). What we also now have in Madison Square Park is art, usually interesting and fun, currently three new stainless steel sculptures by Roxy Paine.

The clear favorite here (at least, of Debbie and myself) is the show's centerpiece, Conjoined, though I think that's far too inactive a name for such a dynamic piece: two full-size industrial trees, set in the middle of the park's largest lawn, one standing tall, the other lurching in, spindly branches touching in dozens of places. Are they dancing...? Battling...? Embracing..?

Also intriguing is Defunct, which greets you as you enter from the southwest corner. Standing in the park's dustiest patch, this is another bright and shiny tree, 42-feet tall, desiccated, broken, and stumpy from age or disease. It's sad but also strong. Paine's third sculpture is the least engaging, we thought. Erratic is a stainless steel boulder that, despite its scales and irregularities, called to mind nothing more than a baked potato.

Madison Square Park is located between 23rd and 26th Streets, and Fifth and Madison Avenues. All three of Roxy Paine's pieces will be up until December 31. Note to out-of-town visitors: Danny Meyer's Shake Shack, which serves better-than-average burgers, fries and frozen custard, has a fanatical following. If you're planning on eating here—and it's definitely a nice spot to picnic—allow at least 45 minutes to get your order.