Narbonne
Narbonne was founded in 118 BC as a Roman port. It's now a city of 40,000 and quite a few kilometres from the sea.
The Canal de Robine - which joins the Canal du Midi - runs through the centre of the city. It's really quite lovely.
The Cathedral and the Archbishop's Palace are worth a visit. So is the covered market, les Halles, next to the canal. It runs everyday from 7 am to 1 pm. There are also open air markets next to the canal on Tuesday and Thursday.
Narbonne Tourist Office - in English
Pictures of Narbonne on Flickr