The planet was home to an outpost called Taonas, which was protected by a powerful shield and equipped with a Zero Point Module. Originally, the planet was quite possibly a world similar to Earth. However, eventually the host star began to die, forcing the Ancients to leave the planet. Over the next few million years the planet was ravaged by volcanic eruptions and lava flows; the Ancient outpost itself was protected by its shield, which created a sphere of solidified molten rock that protected the outpost even after the shield failed. The Stargate of the planet was also lost in this process, forcing anyone who wanted to enter the planet to use a spaceship.
In 2004, Colonel Jack O'Neill, under the influence of the Ancient knowledge downloaded into his mind, brought SG-1 to Praclarush. It was revealed that the outpost was largely still intact and O'Neill used the outpost's star map to show SG-1 the location of the Lost City — Terra Atlantus. Afterwards, he removed the ZPM which the team took with them to power the Ancient weapon platform in Antarctica. (SG1: "Lost City, Part 2")
About two years later, SG-1 traveled to Atlantis to search for information about the Sangraal in the Atlantis database. It was revealed at this time that the database also held information about Praclarush and the fact that it was one of the first worlds colonized by the Ancients. (SG1: "The Pegasus Project")
In an alternate timeline created by Ba'al, SG-1 planned to travel to Taonas to retrieve the Zero Point Module and stop Ba'al from conquering Earth. Unfortunately, Teal'c, Ba'al's First Prime, destroyed McMurdo Air Force Base before SG-1 could reach the Beta Gate, and the plan was abandoned. (Stargate: Continuum)