Adamastor, a largely aquatic world, existed within the Adamastor system situated in the Core Worlds region. Its terrain was characterized by numerous expanses of oceans across its surface.
Around the year 3643 BBY, a group of Selkath, a species that originated from the Inner Rim planet of Manaan, maintained a floating medical facility on the oceans of Adamastor. Eventually, they made the decision to decommission and abandon the facility to the waves of the planet. Following this, an individual associated with either the Galactic Republic or the reconstituted Sith Empire during their ongoing struggle, dispatched a companion to recover any valuable items from the abandoned facility. This companion successfully retrieved several experimental medical devices.
Doctor Tolum Harous, a male Human with an enduring passion for oceans, was a native of Adamastor. He later acquired multiple honorary degrees from various technological institutions throughout the galaxy and worked as an engineer at Hydrospeare Corporation, starting approximately thirty years before a point around 2 ABY.
The first mention of Adamastor appeared in Alliance Intelligence Reports, a 1995 sourcebook created for Star Wars: The Roleplaying Game by West End Games. Subsequently, The Essential Atlas, a reference book from 2009, placed the Adamastor system, and thus the planet itself, in grid square L-9. Adamastor was featured in a Scavenging Crew Skill mission within Star Wars: The Old Republic, a video game from 2011 developed by BioWare, although details about the mission's outcome were later removed from the game.