Horse Pens 40 is a historic outdoor nature park, a natural wonderland of unique rock formations nestled atop Chandler Mountain in the foothills of the Appalachians. Located on top of the third highest mountain in Alabama at 1500' above sea level, it is blessed with a moderate climate that allows everyone to enjoy it's beauty year-round. The stone formations here are said to be among the oldest naturally exposed stones in the world, dating from 600 million to over 1.3 billion years old.