Landscape Arch is an impressive arch that spans more than the length of a football field (the longest in the park and one of the longest in the world). The thinnest part of the arch is only six feet thick. In 1991 some hikers were sitting under the arch when they heard rumbling that sounded like thunder. They scooted out of the way as rocks fell and escaped a 73 foot slab of rock that crashed down. The park closed the trail after that and Landscape Arch is now viewed from a safe distance.