Mistshore was the name given to the dilapidated north shore of Waterdeep's Deepwater Harbor
After the Spellplague of 1385 DR, Waterdeep went into a decline and maintenance of the harbor was neglected. Many ships sank or were scuttled in the northern harbor and eventually Waterdeep's outcasts created a small community on the wrecked ship hulls. The harbor water was polluted and smelled horribly.
In 1491 DR, Mistshore was largely destroyed in a massive fire, with most ships burning down to the waterline and having to be towed out of the harbor to prevent other vessels from running afoul the wreckage. By 1492 DR, most buildings in the neighborhood were still burned and abandoned