Falador Swamp was a large swath of wetland formerly located west of Falador, the capital of Asgarnia. The area extended from Lake Crystalmere near Taverley to the South, reaching near to Falador's western wall until stopping near the Dark Wizards' Tower to the South. The swamp has, since the Year 164 of the Fifth Age, decreased in size to virtual non-existence, possibly due to climate change. They are seen only in the first RuneScape novel, Betrayal at Falador.
The swampland was a key defensive point for Falador and much of Asgarnia. Navigation through the swamp, especially for large military forces, was nearly impossible. The paths through which travel were safe were kept secret by the White Knights and Asgarnian government. During the War of 164, the swamps were a point of heavy conflict between the White Knights, Falador City Guard, and the Thorobshuun - Garagorshuun goblin tribes of the north. They played key roles in the Siege of Falador and the Taverley Massacre.
Since then, the swamps have gradually disappeared and have been replaced with the temperate - frigid forests for which northern Asgarnia is well known. The exact reason for the wetlands' disappearance remains open to speculation, although the most likely culprit is climate or current change in the bordering Southern Sea. There exist minor signs of the swamps today, such as the overgrown tangles near the Dark Wizards' Tower and the entrance to Taverley Dungeon. The western border of Lake Crystalmere still houses some flora and fauna that once inhabited the greater region, including toads and king worms.