The launch of the Low Line exhibit last week previewed the potential of life in subterranean Manhattan. Here we take a look inside the surreal scenes of an underground park, fed by light from fancy new solar technology, and then hang out at as a special benefit held on Thursday night to promote the dream park. Among the guests? None other than Entourage star Adrian Grenier. Now that it’s drawing some star power, it looks like the Low Line might be able to rock some of that High Line magic all the way to reality.