Mander

The Mander is the greatest river of the Reach, and its course and history are set down in The World of Ice and Fire. It rises in the hills near Tumbleton in the northeast of the region and runs southwest past Bitterbridge, taking in the Blueburn near Longtable and the Cockleswent near Cider Hall, joining another river near Highgarden and turning west to pass north of Brightwater Keep before opening into a bay of the Sunset Sea east of the Shield Islands. It is wide and slow, though snags and sandbars make it awkward to navigate, and above Bitterbridge it runs shallow and muddy, passable only to small craft. Garth the Gardener is said to have chosen the site of Highgarden for its nearness to the river, and King Garth VII Gardener fortified the Shield Islands to keep ironborn raiders out of it. House Manderly, who claim the river was named for them, once held Dunstonbury on its banks.