The Kingdom of Maru is a ancient kingdom whose people are known as the Maruvians.
The Maruvians harnessed the most ancient and powerful magic in the world which is stored in the Codex Maru. The sorcerer priests and priestesses of Maru created all sorts of magical artifacts such as the Amulet of Avalor and the Scepter of Light. According to Zuzo, they made all sorts of magical objects. It was a wizard from this kingdom who imprisoned Orizaba in the Spirit World. One day, Maru vanished without a trace, and the Kingdom of Avalor rose in its place. According to Mateo, no one knows what happened to them.
The architecture of Maru appears to be based on the Yucatan Mayan Pyramids as they too lie in ruins, and as stated by the Mateo, the Maruvians disappeared without a trace, the same as for the mayans.