One of many Orochimaru's hideout.
Otogakure (音隠れの里, Otogakure no Sato, literally meaning: Village Hidden by Sound) was Orochimaru's personal village, founded for the express purpose of collecting ninja for his experiments and his quest to learn all techniques. In actuality, Otogakure is not really a village, but a group of hideouts and bases scattered throughout the Land of Sound and various other countries. Sound ninja use a diverse amount of techniques, which are mostly centred around the modifications and mutations Orochimaru gave them.
Ninja from Otogakure.
Team Dosu, under Orochimaru's orders, entered the Chūnin Exams with the goal of killing Sasuke Uchiha. However, Orochimaru was actually using them as test subjects for Sasuke's power after Orochimaru gave him the Cursed Seal. Later, Orochimaru tricked Sunagakure into helping Otogakure invade Konoha. Based on their map, Hidan and Kakuzu visited Otogakure while searching for jinchūriki. With Orochimaru being sealed by Itachi Uchiha, the fate of the village is unknown.