Thornhill (5E)

From publisher blurb:

Standing on the fringes of a vast and noisome swamp, Thornhill is a miserable, hard place of cloying mud, grasping thorns and insular, superstitious folk. There is a little cheer to be had in Thornhill; the few visitors describing it as dull and dreary as the surrounding swamps. For all that, though, a steady trickle of adventurers visit Thornhill for the half-buried and drowned ruins of several tombs are said to lie forgotten in the surrounding marshland and the villagers have friends among the nearby degenerate lizardfolk who make excellent guides in the trackless, far reaches of the swamp.