Limestone Canyon Regional Park is an incredibly beautiful area to hike, but it’s also home to a famous area called “The Sinks,” also known as “the little Grand Canyon of Orange County.” Limestone Canyon hike is not always open to the public, but this easy trail guide will show you how to visit and see The Sinks for yourself. Before visiting Limestone Canyon Regional Park, you must register for an open event. Visit LetsGoOutside.org