Why is that object floating in the Fens?

“South of Hy-Brasil,” an installation by Irish artist Caoimhghin Ó Fraithile, is floating in the Fens.Keith Bedford/Globe Staff/Globe Staff

There’s something peculiar afloat in the Fens, besides the usual thin layers of green algae and a few stray branches.

A temporary art installation, a strange hut straight out of a “Mad Max” movie, has been set up on the water near the Muddy River Park, just beyond the bushy trees and shrubs behind the Museum of Fine Arts.

The display, which has a red-and-white checkered covering on one side, and a smaller thatched roof on the other, is called “South of Hy-Brasil,” an apparent reference to Irish folklore, and was created by artist Caoimhghin Ó Fraithile.

The post-apocalyptic-looking object, which isn’t fully set up yet, is one of two installations that will be on display in the Fens through October, as part of Medicine Wheel Productions’ “Tír na nÓg,” or “Otherworld,” series, launched in partnership with the Fenway Alliance’s Public by Design Initiative.

According to Medicine Wheel Productions, “Hy-Brasil” was a mythical place that for centuries was depicted on maps, off the western coast of Ireland.

“Legend says [it] only becomes visible once every seven years, and is the home of a mysterious advanced civilization,” according to the organization.

Anna White, director of community initiatives at Medicine Wheel Productions, based in South Boston, said the nonprofit’s decision to float Ó Fraithile’s work in the lagoon was an extension of their Brooch Project, an effort to draw more people to the Emerald Necklace, the public green space that stretches from the Back Bay to Dorchester.

“We want to engage communities with public art, and public art experiences,” White said in a telephone interview.

A ceremony and reception will be held in early September, White said, to celebrate Ó Fraithile’s installation, as well as the second piece, “Well House,” by artist Michael Dowling.

Additional works by Ó Fraithile are on view at the Norman B. Leventhal Map Center at the Boston Public Library, in conjunction with the project. There, people can take a gander at sketchbooks and drawings by the artist through the end of October.

“Ó Fraithile’s intricate drawings echo maps found in the collection and invite us to visit the forgotten or hidden lands and places that inhabit our collective imagination,” officials from the center said of the artist’s work.

The map center is also hosting an online gallery of centuries-old maps from their collection that show “the transition of Hy-Brasil . . . from legitimate island destination, to ‘imaginary’ place, to simply a ‘rock.’ ”