In the XVIII century aboard post barge, a vessel not used for transporting the mail but passangers, four days were needed for the navigation between Agde and Toulouse on the Canal du Midi.
The post houses were located in the Somail, in Trèbes, in Catelnaudary and in Négra.
At the Somail you will see the only round tower formerly used as an ice-house still standing on the Canal du Midi. It used to provide ice to the shops and inns and refrechments to the travellers and bargees.