Quote Originally Posted by Throbert McGee View Post
Also, as a rough rule of thumb, the preposition в tends to be used with enclosed spaces, while на tends to be used with open spaces, which is why one says "на Красную площадь". (But on the other hand, there are a lot of exceptions to this, like using в to say "to a city," even though cities don't have roofs and are "open spaces.")
Very nicely noticed