Ardena was a planet in the Milky Way galaxy which was hundreds of years away from Talthus if traveled by sublight. Despite this fact, the Talthuns chose it as their new home following the destruction of their homeworld. They sent three ships, including the Stromos and other two ships, to the planet which each contained more than one thousand of their people each in order to save their civilization.
The Stromos itself crash-landed on P2A-347 before it was able to get to Ardena, and it is unknown if the other two ships arrived at all. When SG-1 discovered the Stromos on P2A-347, they promised to help relocate the people on board to a new planet. Whether or not this was Ardena is unknown, as it is unknown if Ardena even contained a Stargate. (SG1: "Lifeboat")