Chicago-henge: When and how to see the unique phenomena

CHICAGO (WLS) -- Twice a year, a unique phenomena called "Chicago-henge" - based off of Stonehenge - can be seen here in Chicago.

Look down any east/west road in the Loop and you'll see the sunrise or sunset on the horizon. It makes for a beautiful view with the big buildings framing each side.

The reason for this is the perfect east/west layout of the roads in Chicago and the Equinox. Thank the city planners for laying out such a perfect grid!

The Equinox is when the sun's direct rays are right on the Equator. "Equinox" means equal day and equal night. So every place on Earth has about 12 hours of daylight and 12 hours of night.

The Vernal Equinox (Spring Equinox) and the Autumnal Equinox (Fall Equinox) are the only two times of the year where you can see "Chicago-henge".

The Spring Equinox falls anywhere between March 20 and March 23. This year, Spring begins on March 20 at 4:58 p.m.

The Fall Equinox falls anywhere between September 20 and September 23. This year, Fall begins on Sept. 23 at 2:50 a.m.