Located in the constellation Triangulum, M33 (messier 33) is a galaxy often used to determine how dark an observing site is. If M33 can be seen visually (without optical aid) then the observation site is very dark, the degree of nebulosity observed allows a gauge to be made of the sites visual 'seeing' magnitude.
This is a few frames grabbed at my local dark site and stacked. I had some mount issues, hence this image is not as good as it could be. Too much noise, not enough frames.