This image shows 3 common emission nebulae found in the constellation of Sagittarius at a declination of -24 degrees.  

The largest nebula, at bottom right, is M8, nicknamed the Lagoon Nebula. It is located 4000 light years away and is almost 100 light-years across, with an apparent size to us of about three times the size of the full Moon. The large cluster of 100 stars powering the nebula, NGC 6530 just left of its center, is beautiful in itself and would stand out if not surrounded by such a bright nebula.  Dark Bok globules (small inky black winding dust lanes) are scattered everywhere throughout the nebula.   I like how the "water" (blue OIII signal) of the Lagoon seems to be overflowing and running out over the "rim" of the lake on all 4 sides. 

The nebula at left is IC 4685, a beautiful and underappreciated object.  It does not have a nickname, except for the pathetic "The Lagoon's Forgotten Neighbor". Note the winding dark dust lanes, the 2 almost circular emissions (IC 1274 & IC 1275), and the bright orange arcing wall of dust and gas that is next to the open star cluster NGC 6559.

At top is M20, nicknamed the Trifid Nebula because the central portion is divided by dust lanes into different regions, looking a bit like a big peace emblem.

I was originally planning to crop and post each of the 3 nebula separately so that their details are more easily seen, but they seemed like a nice trio so I left them together.  Plus, this wider view shows a glimpse of the dimmer but interesting DSOs which lie between the Lagoon Nebula (M8) at bottom and the Trifid Nebula (M20) at top.   As seen in the mouseover, these include the open star cluster NGC 6546, the emission nebula Sh2-28, and the emission nebula Sh2-26 (the locations of these 2 Sharpless objects are shown in the mouseover to be further right than they are).  A small but interesting pair of objects is seen at 1802 RA and -2341 Dec.  It consists of the open star cluster Bochum 14, surrounded by the red-rimmed emission nebula BFS 1.