Travel Weekly Blog

Every year, groups of New Yorkers take to the streets to capture the sunset aligning perfectly with the east-west lines on the city's grid.

This year Manhattanhenge hit on May 29/30 and again on July 11/12 - I've dug up some embeddable photos from flickr.

by JSchumacher

by effingboring

by marf2010

The American Museum of Natural History explains:

Had Manhattan's grid been perfectly aligned with the geographic north-south line, then the days of Manhattanhenge would be the spring and autumn equinoxes. But its street grid is rotated 30 degrees east from geographic north, shifting the days of alignment elsewhere.

Any city crossed by a rectangular grid can identify days where the setting sun aligns with their streets. But beyond the grid you need a clear view to the horizon, as we have over New Jersey. So Manhattanhenge may just be a unique urban phenomenon.

Update: there's a Wikipedia page about Stonehenge replicas and derivatives around the world. Hat-tip to Triphow.