Never turn left when you see this sign - but, where is it?

Okay, you know everything about Bluffton.

Tell the Icon where one might find this sign? (Denny Morrison is not eligible to enter this because we think he know the answer.)

Here are some hints:

• You'll only find this sign turned on two times a day
• When it turns on it doesn't remain on very long
• It's on the east side of Main Street
• It's a very old sign
• It's message is very wise - it would be very risky to turn left this the sign is on

Answer is the in the photo below:

Railroad Street and East College Avenue