This is the touristy way to do caves in Zakopane, not that there's anything wrong with that - certainly, with full illumination you can see more of the rock formations, and if you slip and bonk your head, there will be a guide to pull you out of the cave. With that said, Mroźna (Frosty) Cave can only be visited from May until October (opening hours roughly 9:00 to 17:00 Mon-Fri, but subject to change), and there is a small entrance fee to be paid - 4zł when we last checked. If you decide to go for it, and the lines to the entrance don't scare you off, you will be given a short lecture (in Polish, of course), before being ushered in through an off-putting man-made tunnel to complete the 500 m dead-end trail on your own. To get to the cave, take the one-way black trail from the bottom of Kościeliska Valley, some 200m past the small shrine (35mins from the trailhead at Kiry); Mroźna will be half an hour up, about 150m from the bottom of the valley. After visiting the cave, it takes another hour to come down, and the trail will spit you out near the Owl Rock. All in all, you should allot at least two hours for this little excursion.