Check out The Runescape Wikia's article here: Gamers' Grotto

Gamers' Grotto is a cave located just north of Falador, which was released when the Wilderness was restored on 1st February 2011. It contains three popular activities: Stealing Creation, Clan Wars and a portal to Fist of Guthix.

Gamers' Grotto Map

Map of the Gamers' Grotto

The Dungeon itself has been given a teleport via the Games necklace, which has replaced the teleports to the Bounty Hunter/Wilderness Volcano and Clan Wars arena. The dungeon was originally believed to be a 'hub' for fans of these activities, (Corresponding with player worries about how these activities would be affected by the return of the Wilderness) while the games themselves would remain in the Wilderness and could be accessed much more easily by the portals here. It was discovered with the launch of the update that the activities were moved here. The area that once held Clan Wars now holds the Bone Yard, an area for F2P players to train the Prayer skill (This addition was part of the original PvP Wilderness.) The area that held Stealing Creation has been only slightly altered, so that the graves that were nearby on the grassy hill have been moved closer to the Wilderness Volcano. The Fist of Guthix activity technically remains in the Wilderness, with the entry now being by portal from the Gamers' Grotto.

The Mystic's Camp, where Stealing Creation is played, is in the North of the dungeon, in the largest room. The entire activity has been moved, including the Rewards trader, portals and game lobbies.

To the South is the portal to the Fist of Guthix activity. Enter the portal and you will be teleported directly to the cave, and exiting the cave will result in returning here. Suprisingly, this leads to the wilderness, although you can't be killed here and the only way out is to use the portal which leads you back to the grotto.
400px-Gamer's Grotto entrance

Entrance to the Gamers' Grotto

The final game in the dungeon is to the East, which is the famous Clan Wars. The portals have all been moved to this location, along with the NPCs related to the activity, such as Larry, who sells team capes to players. For player convinience, there is a one-click Bank Chest in the corner of this room. Surprisingly, this is the only one-click Bank Chest in RuneScape to have a Grand Exchange 'Collect' option.

There was also some speculation that the creatures from the Wildernes Volcano (and possibly the Revenants) would have been moved to this location. However, on 1 February 2011, it was revealed that they resided in the new Forinthry Dungeon.

Information gotten from the RuneScape Wiki