Sephiroth Tree

The Sephiroth Trees are large glowing trees that hold up the Outer Lands above the Qliphoth. There are ten in total. The Sephiroth Trees can be accessed through the passage rings, which are marked usually by ruins that date back to the Dawn Age of Auldurant, or possibly earlier. Each tree sustains and supports separate regions of the world, and if the associated tree is destroyed, the immediate area will implode and collapse into the Qliphoth, leaving a massive abyss on the surface in place of the former landmass. Parts of the regions may be supported by multiple trees, so the collapsing effect might be delayed or avoided in some areas.

The Sephiroth Tree at Hod had been destroyed several years before the game's events, by a forced and mechanically-induced hyperresonance with Van Grants when he was younger, causing the entire continent to be destroyed. Its original location is marked by the entry and exit point between the Qliphoth and the Outer Lands, although an intact Sephiroth Tree and passage ring appears within the replicated Eldrant, providing it with the aerial capabilities it exhibited towards the end of the game.

A similar event happens to the Sephiroth Tree at Akzeriuth, in which a forced hyperresonance by Luke fon Fabre causes the destruction of a large part of the continent of Rugnica, causing the deaths of everyone living in the region. Later actions by the party involve the overriding of the trees' links to allow the Outer Lands to be lowered safely into the Qliphoth. The collapsed region had already been disintegrated by the time the Outer Lands were lowered, so that area became an extension of the ocean.

Locations
The regions that associate with the Sephiroth Trees (labeled by the location of their Passage Rings) are as follows, listed in the order the game provides for numbering them:
 * 1. Radiation Gate
 * 2. Absorption Gate
 * 3. Northeastern Rugnica (St. Binah and Engeve) - Shurrey Hill
 * 4. Aberria (Baticul, Belkend, Chesedonia) - Zao Ruins
 * 5. Southern Rugnica (Akzeriuth and Kaitzur) - Akzeriuth Mine Shaft 14
 * 6. Ispania and Northwestern Rugnica (Grand Chokmah) - Tataroo Valley
 * 8. Isle of Hod (Feres, Eldrant, Yulia City) - Eldrant

Unnumbered:
 * Radessia (Sheridan) - Meggiora Highlands
 * Padamiya (Daath) - Mt. Zaleho
 * Sylvana (Keterburg) - Mt. Roneal

Etymology
The Sefirot is a term that derives from the Jewish Kabbalah, representing the ten attributes of God.

Trivia

 * Several locations in Tales of the Abyss were named after the branches of the Jewish Sefirot.
 * Keter/Keterre - Keterberg
 * Chokmah/Hokma - Grand Chokmah
 * Da'at - Daath
 * Hod - Hod
 * Hesed - Chesedonia
 * Malkhut - Malkuth
 * Binah/Vinagh - St. Binah