The Astromy Castle is the only place the two races can speak, trade and etc.
Angels/Demons are part of the chosen three in the Astrilogical Ordinis.
Celsius- The angels live here. It's a peaceful region, and the only way into Angel Falls. It stays in the 70-80's in terms of weather. Flying is popular here.
Fahrenheit- The demons live here. It's dark and depressing, with the occasional volcanic eruption. That's why their cities are built on the rocks.