Le Yaudet (in Brittany, France) is a promontory of granite commanding the estuary of the river Leguer down-river from the modern town of Lannion (Cotes d'Armor). It has long been known as the 'Old Town' ( Civitas vetus in Latin documents and Coz Yaudet in Breton) and Iron Age, Roman and medieval finds have been made from time to time over the last two centuries. A programme of research excavations began in 1991 and continued annually until 2002. The results of the work show the site to have been in use almost continuously from the early prehistoric period. This is the second volume and deals with the Prehistoric period, continuing up until the end of the Gallic Empire.