Glossary
Heaven and hell
In one line: Two common area names: heaven is a high spot overlooking a site, hell is the spot underneath.
What it means
Many maps have a heaven: a raised position, often a balcony or window, that overlooks a site. The spot underneath it is often called hell. These callouts are so common that they get used on different maps.
Heaven gives a great view but exposes you to many lines of fire; anyone entering a site must remember to look up. Hell, on the other hand, is a tucked-away corner by the wall under heaven.
An example
You walk into the site and hear a shot from above. You call "heaven": everyone knows the enemy is on the balcony overlooking the site, and the next player in checks there first.