The planet Iradon is located in the Alpha Quadrant when it is in the prime universe. The planet is shrouded in a cyclic interdimensional Rift which causes it to appear and dissapear from the Prime Universe on a 1,000 year cycle. The presence of the planet in the prime universe is relatively short lasting roughly 30 standard days.
In 2407, a shuttlecraft carrying Eva Straton was cught up in the gravity well of the planet when it suddenly appeared in this universe. Starton crashed on the planet and lost her Memory. Her innate telepathic abilities caused the local Iradonians, whose culture was roughly technologically that of Medieval Earth to worship her as the Annointed.
They eventually managed to rescue Eva, and with significant modifications to the crashed shuttlecraft managed to return to their own dimension where they were rescued by the USS Kitty Hawk.
During their time their the Chief Engineer of the Boudicca met Arania, a native Iradonian and after they fell in love he brought her back to the Prime universe. As a result when the planet shifted back to it's normal universe, Arania became the only member of her species in the prime universe.
The culture of the iradonians is derived from Iconian, and there are signs of Iconian Architecture, technology and language there. The Interdimensional Field, whether by design or incident prevents advanced technology from working there.
The planet is next scheduled to return to this universe in 3407.