Synod

Synod was a Netherese floating citadel. It was an ecclesiastical enclave ruled by a pious archwizard. The city was home to some of Netheril's finest cathedrals.

History
Synod was widely believed to have been over the Sea of Fallen Stars when Netheril collapsed and the flying citadels fell from the skies, and thus lost to the depths.

However, storms over the sea had forced Synod to return early and the city was above what was later the Stonelands when Karsus's Folly erupted. The city was at a relatively low altitude when it fell so it was not totally destroyed by its fall. Instead of being destroyed, the enclave fell in upon itself digging into the rough terrain of the Stonelands. Blowing sand and rockslides then buried and disguised the ruins of the city, hiding the former citadel from history.