Most small-molecule neurotransmitters are stored in small vesicles that range from 40 to 60 nm in diameter and, in electron micrographs, appear to have clear centers. The vesicles that store neuropeptides are larger, ranging from 90 to 250 nm in diameter.
The world's largest concentration of natural sandstone arches. 1  Hike the 1.5 mile trail leading to the base of Delicate Arch to experience one of the most breathtaking vistas in the world. 2  Your family will love the short trails in the Windows Section that lead right up to several massive arches.
Where. USA Arches National Park,Utah. The longest natural arches in the world are both in Utah, USA, which span openings of equal width. Landscape Arch, in Arches National Park, and Kolob Arch, in Zion National park, both stand over openings 94.5 m (310 ft) wide.