The Throne is both a reference to Siddharta Gautama's royal ancestry and to the idea of spiritual kingship - enlightenment as ruler of the spiritual world. The ancient stone carvings above show the Dharmachakra and the Bodhitree on top of the throne. Sometimes the base of the throne is decorated with other symbols such as lions and deer, both associated with the Buddha's teachings.
The throne is symbolic of the royalty to which Siddharta Gautama belonged initially as well as the dominance He achieved over the spiritual world later in his life. The throne is usually seen with the dharmachakra and bodhi tree on the top. At the base, symbols such as lion and deer can be seen in few cases.