Lost Mines of Phandelver
This small human mining town used to trade in the mithril that flowed from the Sword Mountains. Now the locals mostly trade in iron, copper, and nickel. It lacks a proper port and moves most of its wares via barges pushed out to sea through the swampy coastal marshes to the west.
Long ago, Leilon was the site of a prominent mage's circle. However, during the Spellplague, the tower's wards erupted with wild magic, releasing all manner of guardian monsters and extraplanar oddities. Fortunately for the town, one of these wards also sealed the tower within a magical shell. Nothing has entered or left the tower in ages, but the locals still report odd sounds and lights emanating from deep within.