Fat Man’s Pass is a popular day hike in South Mountain Park, just south of downtown Phoenix, Arizona. The Pass is a narrow slit between two huge boulders leading to Hidden Valley. Both attractions, Fat Man’s Pass and Hidden Valley are along the 15 mile long National Trail. The National, as it is known, follows the ridge line of the South Mountain, a granite ridge running east and west on the edge of the Salt River Valley. This 17,000 acres park is one of the largest city parks in the world and enjoys a huge number of visitors each year. There are over 58 miles of trails for hikers, mountain bike riders and horse riders. The trails vary from easy walks to rugged hikes through rough and steep terrain. The highest point in the Park accessible by trail is Dobbins Lookout at 2,330 feet. You are as likely to see seasoned outdoor types hiking or running the trail as you will young people with babies. All the trails are rocky and steep. You might encounter desert animals, including rattlesnakes. Just give them plenty of room and keep going. Always carry plenty of water with you, wear sturdy shoes, a hat and sunscreen. Some of the Parks attractions are accessible by car and there are several spectacular overlooks that give panoramic views of the valley.