On the island of Manhattan, in New York City, the roads are arranged  in a grid: avenues run north and south, streets run east and west.

Twice a year, in an event known as Manhattanhenge, the sun sets in  precise alignment with Manhattan's streets, illuminating each street  for about the final fifteen minutes of each day.

Astrophysicist Neil deGrasse Tyson compares this event to Stonehenge and the summer solstice:

"What will future civilizations think of  Manhattan Island when they dig it up and find a carefully laid out  network of streets and avenues? Surely the grid would be presumed to  have astronomical significance, just as we have found for the  pre-historic circle of large vertical rocks known as Stonehenge, in the  Salisbury Plain of England. For Stonehenge, the special day is the  summer solstice, when the Sun rose in perfect alignment with several of  the stones, signaling the change of season."

This year's Manhattanhenge occurred on May 30, but you'll get a  second chance on July 12, when half of the sun will illuminate  Manhattan's street grid, as in the photo above. On July 13, you'll see  the entire sun on the horizon.