This is a place where Jinchuriki Hangout and chatter. The entrance can only be summoned by a Jinchuriki's chakra level or Sora(has part of the Nine-Tails Chakra[he is acceptable - Sora Jinchuriki]) Other nins that follow a Jinchuriki to this place would be lost and sent back where they started. This area is nearly impossible for enemy ninjas to find. This area can be different to Jinchuriki if wanted. Example: Nine-Tailed Chakra could transform the area into a lush, green forest and the Seven-Tailed Chakra could make the area a barren wasteland and they would only see the area through their own eyes and be able to talk to each other in the abandon cave that is the Jinchuriki Hideout.

Jinchuriki Info:

http://naruto.wikia.com/wiki/Category:Tailed_beasts

Tailed Beasts History:
The Tailed Beasts have been around before the First Great Shinobi War. Because of their immense power, the shinobi from each nation tried to use the Tailed Beasts as military weapons during the Shinobi Wars. After the Wars, Hashirama Senju, the First Hokage, managed to capture and control them with his Wood Release techniques, and used them as a peace treaty to the other great shinobi nations, in order to stabilize the balance of power between them. After his death, however, the shinobi nations couldn't control these giant demons themselves and they began to run wild. Their attempts to capture them and harness their immense power failed as no nation could control such power. Instead, the nations moved to capture the Tailed Beasts and seal them within humans, which they were called Jinchūriki. This method worked and by the time period of the series, the only known Tailed Beast to have not been sealed into a human was the Three-Tails.

Legend of the Tailed Beasts:
According to some fans, the "Legend of the Tailed Beasts" is an epic story from Japanese folklore which Naruto author Masashi Kishimoto draws from to create the Tailed Beasts in his work. However, it is an example of internet-based fakelore which originated on Chinese websites, some suspect this chinese site.

The veracity of the legend breaks when it is cross-referenced with non-fandom sources on Japanese folklore. For example, the isonade, which is held to be the Three-Tails in this account, is in fact equipped with only one large, hook-covered tail, and the "houkou" which is actually a Chinese creature called penghou, named as the Five-Tails, has no tail at all. The badger was said to be the lord of all these beasts in the original legend, and Naruto fans have claimed certain Bijū to be a badger instead of it's true form which was a tanuki for Ichibi no Shukaku and a bat for Shichibi no Makumore)

Additionally the author of the story admitted it was not a true legend, unfortunately it has gone largely unnoticed by most fans of the story.

Jinchuriki and their Bijū:

-One-Tailed Shukaku: It is said to be a corrupted spirit of a Sand monk from Sunagakure that turned into a demon. It was originally sealed inside a teakettle. (the demon that was in Gaara) (Ayko)
-Two-Tailed Demon Cat: Is a fire-breathing, flaming nekomata, the beast was said to be a spirit of vengeance. (D.C.)
-Three-Tails: a gigantic, turtle-like demon (early scene)
-Four-Tailed Beast: Four Tailed-Yumi
This was the god of thunder but was changed into a beast by the Eight tails power. The four tails can release a tremendous amount of electricity to help him in battle. Sarutobi used a move known as Kinjustsu Raikiri to cut through the lightning released by the four tails. (iMikami)
-Five-Tailed Houkou: Is a bijuu which looks like a five-tailed dog. Houkou will willingly destroy the nature to obtain the power he desires from these elements.Strangely enough, he is the god of Illusion. Each of the tails possess one of the five elemental powers, that used simultaneously can cause a big earthquake. (Seiryu)
-Six-Tailed Tsume: Has the uncanny ability to form bombs out of clay Not only can it make clay bombs. It can clear mountains with a swipe of it's sharp claws, dig massive traps, in which filled with jagged rock, or lined with opened pockets of noxious gases. (Kuronu)
-Seven-Tailed Cerberus: A three headed wolf that has seven tails that cause earth quakes just by a mere lash. This is one beast you don't want to see in battle. Summoning this beast uses alot more chakra than some can handle and also uses either two wolves and the summoner or three wolves. It had the power to duplicate itself when the akatsuki were looking for it before, it could only do it once so it could protect Shadow's whereabouts.(Shadow)
-Eight-Tailed Ox:ushi-oni (ox demon)
-Nine-Tailed Demon Fox: a single swipe of one of its nine tails can raise tsunamis and flatten mountains.(Yaroki)

Other:
Sora's Jinchuriki form: Ryu