Under the BRIDGE... Bridge... bridge... Traditional Cache

My son and I love walking the trail that runs from Andrews Park along the creek here under the bridge, and is where he first learned tha concept of what an echo was.  

You can only hear an echo if it comes back more than 0.1 seconds after the original sound.  Sound travels 34 m in 0.1 seconds, so you only hear echoes from surfaces that are at least 17 m away.  Smooth hard surfaces give the best echoes because they break up the sound waves the least.

This hide is accessible from the path underneath the bridge. If you stand next to the end of the guardrail and face the water you can hear your voice echo back to you perfectly. Following the guardrail up the hill a bit will lead you to a wooden post without a fence, and the cache will be nearby.