Sept. 23 (UPI) -- Monday marks the beginning of a twice-annual phenomenon known as "Chicagohenge," when the sun aligns photogenically with the grid of Chicago's streets.
The phenomenon, which coincides with the spring and fall equinoxes -- March 21 and Sept. 21, respectively -- lasts for about a week and features the sun rising and setting in line with the buildings on Chicago's east-west streets.
Michelle Nichols of the Adler Planetarium said one of the best spots for viewing is at the western end of the 606 Trail.
Weather forecasters said Monday evening would likely offer the first good look at the phenomenon after rainy weather during the weekend.
Experts said Chicago's grid is better lined up than the more well-known Manhattanhenge in New York.