Post your guesses in the comments section below.
Guess correctly and be crowned "Castro Valley know-it-all" for the week.
Brownie points to the person who can tell us what it's a symbol of.
Congratulations to for correctly guessing The symbol is of a picnic table and it can be found at
Have your own photos around town that you'd like featured in our Castro Valley photo challenge? Send them to email@example.com and see if you can stump our readers!