Ama-no-Iwato (天岩戸) literally means "The cave of the sun god" or "heavenly rock cave". In Japanese mythology, Susanoo, the Japanese god of the seas, was the one who drove Amaterasu into Ame-no-Iwato. This caused the sun to hide for a long period of time.
In order to get Amaterasu out of the cave the other gods threw a party outside. When she heard the noise she got curious and peeked but got blinded by the mirror Yata no Kagami and so she thought they were celebrating the arrival of an even greater and brighter goddess than herself. Though in reality it was her own mirror image. Then Tajikarao forced the cave to open up the rest and the world was bathed in light once again. As Amaterasu stepped out of the cave a holy seal was applied to it so that she couldn't go back into hiding.