Tonight was one of two opportunities this summer to see the phenomenom known as Manhattanhenge. This is when the sunset aligns with the grid of Manhattan similar to how it works at Stonehenge. Astrophysicist Neil DeGrasse, who coined the term, says that the next time to see it will be July 11th/12th. Actually you can still see part of it tomorrow. On one night, the sun is aligned just above the horizon while on the other night it is half above and half below the horizon (depends which part of summer you view it as to the order). According to this blog, the best places to view it are "14th, 23rd, 34th. 42nd, and 57th street, all of which head straight across without obstruction", and you want to get as far east as possible. You can see a cool time lapse video of it on YouTube.