Upper Las Virgines Canyon Open Space Preserve is 5,600-acres with miles of trails in the Simi Hills at the western edge of the SF Valley. Barbara and I had this hike on our list for months, waiting out fires, rainstorms, and hot weather for a bit of spelunking because...caves are fun! Worth the wait to visit what I'm convinced was a Chumash Indian playground and spiritual center sometime within the 11,000 years the Chumash had SoCal to themselves before the Spanish showed up. Munits, the namesake of our destination cave, was a Chumash shaman—the second most powerful person, and principle religious figure, advisor, and medicine man (or woman) in the tribal hierarchy. Folklore is thin, but it's said that the cathedral-like vertical, chimney cave was Munits' home until he was killed by the talons of an eagle after murdering the son of a politically important chief. The cave is allegedly haunted by Munits' spirit (though we didn't get deep enough inside to find out.) The preserve area is easy to find. Take the Valley Circle Blvd exit off the 101, drive north for 2.1 miles to Victory Blvd. Turn left to the trailhead that begins where Victory Blvd. ends. Park in the lot ($3), and start north up the trail, the first road immediately behind the info kiosk. Easy! A nice wide trail with a bit of an incline then decline for the first mile. No big deal. About a mile in, the cave-dotted mountains come into view, the caves looking like ant holes from a distance. At 1.4 miles, take a left at the Hunter Allen Trail marker. This is where the hike heads up, up, up and gets tricky. Loose gravel and deep ravines surrounded by dry brush had us scrambling for a foothold the quarter mile up to the caves dotting the mountainside. You can't miss Munits' Cave at the top of the gutted trail, and up close—wow! Though we wanted to go inside, the first step was too steep for me to catch a decent foothold so we opted to circle parts of the mountainside trail, explore the smaller caves, and then we hiked to another rock grouping with caves we could get inside. This hike was fun, a bit tricky, yet so interesting to see up close how nature carves herself into the most fascinating shapes. Sturdy shoes and hiking gloves are a must; and we recommend avoiding the area after rains (too steep to navigate muddy trails) or during a heat wave. There is no shade. Nevertheless, a terrific hike for explorers at heart, with tons of alternative trails/caves to investigate.