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.
Gateway Arch -- Jefferson National Expansion Memorial. 630 Feet. The Gateway Arch is one of the newest monuments in the National Park system, and at 630 feet, it is certainly the tallest! The Arch is 75 feet taller than the Washington Monument and over twice as tall as the Statue of Liberty. The 60-foot heads carved on the face of Mount Rushmore are designed to the scale of men who would stand 465 feet tall, a height that would easily allow such giants to walk through the legs of the Arch!