From Agde, take the D51 to Marseillan, another ancient port, initially settled by the Phoenicians.
The D51 is part of a network of shuttle buses catered to tourists. 
mnli hypothesis: The D51 is part of a network of shuttle buses catered to tourists.  premise: From Agde, take the D51 to Marseillan, another ancient port, initially settled by the Phoenicians.