Mtwara's main market is the practical heart of the region — a large and busy place where the produce of southern Tanzania's farms, the catch from local fishermen, and goods from as far as Dar es Salaam and Mozambique change hands. It is not a tourist attraction but a working market, and it shows.
The fish market section is worth seeking out: the Indian Ocean's catch here includes species rarely seen further north, and the fishing community at Mtwara still operates largely by dhow and small boat. Early morning is the best time to visit. The wider market is good for fresh fruit and vegetables at prices far below what you'd pay in Zanzibar or Arusha.