Thalys is a high-speed train network built around the high-speed line between Paris and Brussels. This track is shared with Eurostar trains that go from Paris or Brussels to London via Lille and the Channel tunnel and with French domestic TGV trains. The trains belong to the TGV (train à grande vitesse) family of high-speed trains.
Beyond Brussels, the main cities Thalys trains reach are Antwerp, The Hague, Rotterdam, Amsterdam, Liège, Aachen and Cologne. Trains to these destinations run partly on dedicated high-speed tracks (some of these are yet to be built), and partly on older tracks shared with normal-speed trains.
The link with the Charles-de-Gaulle airport allowed Air France to cancel its air service between Paris and Brussels; instead, Air France books seats on Thalys trains.
Travel time from Brussels (Gare du Midi/Zuidstation) to Paris (Gare du Nord) is normally 1 hour, 25 minutes, for a distance of approximately 300km.
Thalys has been given the IATA designator 2H. This is used in conjunction with American Airlines and Northwest Airlines. American Airlines has a codesharing agreement with Thalys for rail service from Charles De Gaulle airport to Brussels's Midi. Northwest has a codesharing agreement with Thalys for rail service from Schiphol airport Amsterdam to Antwerp's Berchem Station and Brussels Midi.
Plans to continue the line to Cologne further to Frankfurt had to be abbandoned because of the insufficient power the Thalys trainsets generate when operating under the 15 kV voltage system used in Germany.