The Omega Nebula, also known as the Swan Nebula, is an HII region in the constellation Sagittarius. It was discovered by Philippe Loys de Chéseaux in 1745. Charles Messier catalogued it in 1764. It is by some of the richest star fields of the Milky Way, figuring in the northern two-thirds of Sagittarius.
Kitt Peak National Observatory supports the most diverse collection of astronomical observatories, and is located 56 miles southwest of Tucson in the Schuk Toak District on the Tohono O'odham Nation. It has a Visitor Center open daily to the public.
Source: Wikipedia, the free encyclopedia (https://en.wikipedia.org/wiki/Eagle_Nebula)