Tower of Terror

The Zuul Tower, nicknamed the Tower of Terror by Leaf City's residents, is a haunted tower of unknown origins, only seen once.

History
The tower's exact origins are unknown, but what is confirmed is that the Zuul Tower was named after Muffin Zuul, who died in the building and is said to haunt the place.

Season 1
The tower is seen in "The Halloween Thing", when Alex and the gang walk right past it, greeted by the ghost of Muffin Zuul.