Relto is a somewhat barren age that consists of a small island surrounded by clouds. Explorers have their own small hut in the middle, which contains a bookshelf for linking books and Bahro stones (which become available after linking to them once), a dresser, a bed and a second smaller bookshelf which contains journals. It also has a small tree growing just outside the hut.
Though Relto is barren at first, players can find Relto pages that add features to the age, such as waterfalls, distant islands and even rain. These features can be activated or deactivated at any time, allowing explorers to have their own customized Relto age. Relto was written by Yeesha to be similar to Myst Island. As such, many landmarks are in similar locations to where they were on Myst. The hut assumes the position of The Library, while the tree outside is in the location of the tree leading to Channelwood's linking book. Players can also add a dock with a Relto Page, which is in the location of Myst Island's dock that harbors the ship containing the Stoneship linking book.
There are many oddities about the Relto age that make it unique. The first is that each person who owns a Relto linking book links to their own personal version of the age, unlike normal linking books that link everyone to the age in the Descriptive Book. It is confirmed that this is not merely for gameplay purposes in Uru: To D'ni, where Explorers can link to both their own Relto age as well as Phil's Relto age, which is more customized than the player's.
The second oddity is that players retain their linking book to Relto, even after linking there. When linking normally, a person retains all their possessions but leaves the linking book behind. However, when linking to Relto, the book links with the person.
The third is the ability to link to the age within the age. This is stated by the D'ni as an impossibility, however, an explorer can link back to within their hut at any location within Relto (or any age).
The fourth is the ability to add "Relto Pages" (pages with symbols on it), which alters the age in different ways depending on the page and can be deactivated at any time from within the book.
These impossibilities are explained in the ending of Uru: Ages Beyond Myst, where Yeesha states that her ability as a writer has surpassed even her own father and she has even found ways around the limitations of The Art, which she proves by making it rain in The Cleft.
Relto can be customized with several pages known as Relto Pages. These pages are scattered throughout the ages of Uru and must be found. Each page contains one Relto customization that can be activated or deactivated at any time. Below is a list of Relto pages and what they do.
Uru: Ages Beyond Myst
- 1: A page found in Teledahn that changes the type of roof on the hut.
- 2: A page found in Gahreesen that adds sticks and rocks to the ground.
- 3: A page found in Gahreesen that adds a waterfall and a lake.
- 4: A page found in Kadish Tolesa that allows the trees to grow over time.
- 5: A page found in Eder Kemo that adds symbols and a rug to the hut.
- 6: A page found in The Cleft that makes it rain.
Uru: To D'ni
- 1: A page found in the neighborhood that adds more islands to the scenery.
- 2: A page found in Teledahn that adds a dock on the side.
- 3: A page found in Ae'Gura that adds stars.
- 4: A page found in Great Zero that adds an imager.
- 5: A page found in the Great Shaft that adds a music player.
- 1: A page found in Ahnonay that adds a D'ni clock.
- 2: A page found in Er'cana that adds fire marbles.
- 3: A page found in Myst that adds a fireplace.
- 4: A page found in K'veer that allows plants to grow.
- 5: A page found in Kadish Tolesa that adds butterflies.