To walk the upper Cooper River trail is to discover a secret hidden in plain sight. Who knew so much woodsy, watery, almost-wilderness awaited visitors to this corner of South Jersey, where Cherry Hill and Haddonfield meet? "I've lived here all my life," says Bob Feltoon, an attorney from Voorhees. "I take Park Drive all the time. And I've never walked back here." Says Merchantville businesswoman Marilyn Axler, an active gardener and park patron, "I didn't know about this." http://bit.ly/Xdni6d