Memory altering Statue

See this island right there? It is well known by sailors and explorators in this area. People who have travelled there say there's a statue there, in the middle of the island... and that's it. People who travel there seem to forget every single thing they see and do, from the moment they reach the island to the moment they leave it, except the fact there is a statue there. No matter how long they stay there, they won't remember a thing. They don't seem harmed by the island in any way, nor do they have any kind of lasting effects after being there. They just go, come back, and the only thing they seem to remember is that there's a statue there. Wizards don't seem to be able to detect anything weird from the island, but they too are affected by this mysterious phenomenon.
We don't even know what's the statue of. They just say there's a statue... and that's it.
Category:Geographic location
Category:Anomalous properties
Category:Giantstep