Pelagon was a planet in the Pelagia Province of the Tapani sector and was the capital world of House Pelagia. It was a planet with a long tradition of providing many Jedi, such as Taj Junak. As a result, it was stripped of much of its power during the Great Jedi Purge.
It was an oceanic planet of warm waters and a pleasant climate which made it an attractive site for the early colonists who came to the planet nearly 13,000 BBY. The colonists gathered raw materials from surrounding ore-rich worlds and built huge platforms above the waterline where great cities, called seascapes, were erected. Some of these artificial landmasses were kilometers across and at the height of Pelagia's influence were over 20 in number. With the help of House Mecetti the Galactic Empire destroyed all but two of these platforms during the Jedi purge and downfall of House Pelagia. Pelagon's capital city of Pelagar was situated on the largest of these surviving platforms and spanned over 20 kilometers. By the time of the Battle of Hoth, four additional platforms had been re-built from salvaging parts from the other platforms.
At the bottom of the oceans of Pelagon there were ancient ruins that pre-dated the arrival of the colonists. As part of House Pelagia's secretive reconstruction and build-up program these constructions were utilized to build research stations, storage depots and hideouts.
Prior to the devastation of the planet by the Empire and House Mecetti, the planet's oceans were full of life ranging from plants and fish to giant aquatic reptilians. The contaminants released into the ocean from the bombing of the platforms and the wreckages of hundreds of starships resulted in approximately 90% extinction of aquatic species.