Valyria

Valyria is a dead nation that was located on a peninsula on the continent east of Westeros in George R. R. Martin's A Song of Ice and Fire series, and is the ancestral home of the Targaryen family, who brought dragons to Westeros and used them to conquer the kingdoms there.

Valyria no longer exists, as some as-yet undescribed "Doom" was visited upon it several hundred years prior to the events of A Song of Ice and Fire.