The park, which cost $260 million, opened in May, and it has been enormously successful with the public. Access is free, but after noon you must present a timed-ticket for entry, and it was likely at capacity when I visited in June. It contains two performance spaces, including an amphitheater with the Hudson River as a backdrop, multiple pathways and varied topography, some 350 different species of shrubs, flowers and trees, a grassy spot for lounging and a central plaza with food for sale. The landscape, designed by Signe Nielsen of MNLA, is varied and intriguing, full of small surprises carefully packed into a space that feels larger than it really is. Eventually, some of the trees in this odd patch of landscape, hovering like a mirage over the river, will reach 60 feet in height.