Cold Water Cave Trail is a standout hiking destination in Coldwater, IA, covering 1.5 miles with 100ft of elevation change. Stats: 1.5 miles, 100ft gain, Easy. Type: Out-and-Back. Surface: Rocky. Time: 1 hour. Fee: $8/person. Dogs: No. Permit: No. Wildlife: bats, cave crickets, deer. Best seasons: Longest cave in Iowa. Pack water, layers, and appropriate footwear. Conditions vary across IA. Leave No Trace: stay on trail, pack out all waste, respect wildlife.