Wow. This is a very beautiful place we call Earth.
You’re going to get a lot of interesting answers to this one.
However, in my mind, after having traveled to 37 countries on five continents during my life, your question brought one thing to my mind: Lake Louise in the Rocky Mountains, Alberta, Canada. It’s about the most beautiful sight I’ve ever seen. It’s glacier fed, which makes the water such an incredible aqua color.