(this page is part of the Harvard Univesity Astronomy 208 web site)
The Ground Based View of the Eagle Nebula (image above) reveals "pillar-like" features which appear to be buried deep within the nebula. The high-resolution HST view of the "Pillars" of M16 shows them to contain strange features on their surfaces. These features are referred to as "EGGs" or "Evaporating Gaseous Globules." They are thought to be dense star-forming cores whose environs have been blasted away by photons and winds from the newly-formed massive stars in the region. An explanatory cartoon of this process has been provided at the HST Web Site.
Many views of the Orion Nebula can be found through the "Web Nebulae" site. For the best high-resolution composite view, check out the Orion Nebula mosaic from HST (shown above), which has a little ground-based data added in around the edges. The "bright bar" near the lower left of the image above is also known as Orion Ridge. This "bar" or "ridge" is actually a relatively flat region, seen end-on. In other words, it is primarily a column-density enhancement. This illustration from National Geographic shows the overall geometry of the Orion Nebula.
Information on the "PROPLYDs" evident in the Orion Nebula mosaic can be found through here.
In 1997, the NICMOS near-IR camera was used to observe the OMC-1 region of Orion, which resulted in this image
Perhaps the single most impressive H II region near the Milky Way is the one created by R136, a dense cluster of young hot stars in the center of 30 Doradus (image above) in the Large Magellanic Cloud. The HST images of R136 reveal a higher concentration of early-type stars than any known in the Milky Way.
The very large H II region NGC604 resides in a spiral arm of the Galaxy M33, and is easily visible in ground-based photographs. The HST image has the resolution to reveal the cavity carved out by the winds and photons from the hottest (and youngest) stars at the core of this massive star-forming region.