Termina is the main setting of The Legend of Zelda: Majora's Mask. Link ends up here after falling down a hole in the Lost Woods while pursuing Skull Kid. The Happy Mask Salesman describes Termina as Hyrule's mirror dimension, and it contains many similarities to the land of Hyrule, yet also several differences. The country is separated into four cardinal directions, each under the protection of four guardian deities known as the Four Giants. At the center of the land is Clock Town, Termina's capital and largest city, ruled by Mayor Dotour.
While some people in Termina resemble and even share names with people from Hyrule, their personalities may be vastly different.
There are four main gates that point towards various locations of Termina. The North Gate aims toward Snowhead and the Goron Shrine, the South Gate leads to Romani Ranch and Woodfall, the West Gate heads towards Great Bay and Zora Hall, and the East Gate beholds the haunted Ikana Valley.
Snowhead was named well for it's snow covered mountains. Upon first arrival, snow covers the high peaks to the bottom of the valley. After Link defeats the dungeon boss of the area the tormenting blizzards cease and the perpetual winter season transforms to spring. Snowhead is most well know for containing the Goron Shrine, home of Termina's Gorons, rock-like men seen previously in Hyrule.
Another location to note in Snowhead is the blacksmith's log cabin. In here resides the Snowhead Blacksmith's, most well known for smithing Link's sword to make it stronger and more powerful.
To the South is Woodfall, a swamp-like area filled with octorocks, monkeys, and dekus. Located here is a swamp Tourist Info Center and Kotake's Potion shop. At the Tourist Center, you can have a tour boat chartered for you to easily access other parts of the swamp. Kotake's Potion shop sells potions of course.
You can reach the Deku Palace on foot using Deku Link, or get a safe trip on the tour boat. Inside the Deku Palace is the Deku king and his subjects, along with a monkey heading towards an unfortunate fate.
On the opposite side of the river is the Woodfall temple. Until the boss of the temple is defeated, the waters of the Deku side of the swamp are poisonous.
If you leave the South Gate but break right instead of heading towards Woodfall, you'll arrive at Romani Ranch, equivalent to Lon Lon Ranch from Ocarina of Time. The entrance road is blocked by a large boulder and requires a powder keg in order to be destroyed.
The ranch is named after the owners sister, Romani, with the owner being Cremina. The ranch is famous for its Romani Milk, a substance that can give Link an endless supply of magic.
To the East of Clocktown is the haunted Ikana village. There are many stories that the place had once flourished with kings and its people. However, they've all passed on and recently things have gone amuck. The area is crowded with poes, redead, and gibdo.
There's a small house surrounded by gibdo in the village. To the left is a hill, and atop that a well, littered with gibdo inside. There also seems to be a house of poes.