Sundial Bridge at Turtle Bay

The largest sundial in the world is in Jaipur, India, but the Sundial Bridge in Redding, CA is no less impressive. This multi-million dollar bridge is only accurate on one day of the year - the summer solstice. If you care about that kind of stuff, you may want to plan your visit on June 20 or 21. Other notable events include Think Pink Day, an annual occurrence where the entire bridge is lit up in pink lights.