throne

Definition:

A throne is a specially-designed chair where a ruler sits when he decides important matters and listens to requests from his people.

A throne is also a symbol of the authority and power that a ruler has.
The word "throne" is often used figuratively to refer to the ruler, his reign, or his power. (See: metonymy)
In the Bible, God was often portrayed as a king who sits on his throne. Jesus was described as sitting on a throne at the right hand of God the Father.
Jesus said that heaven is God's throne. One way to translate this could be, "where God reigns as king."