"There are two main reasons to visit this small midtown park, which takes up the three city blocks between Madison and Fifth avenues from 23rd to 26th streets. The first is that its lawns, benches and temporary art installations all have views of the dramatic Flatiron Building—the wedge-shaped tower made famous in Alfred Stieglitz’s 1903 photo. The second draw is the original location of Danny Meyer’s now legion Shake Shack chain—where the ShackBurgers and frozen-custard milkshakes are worth waiting in line for."