Eurostar.

Eurostar is a high-speed railway service connecting London with Paris and Brussels. All it's trains traverse the Channel Tunnel between the United Kingdom and France. The London terminus is St Pancras International with the other British calling points being Ebbsfleet International and Ashford International in Kent. Calling points in France are Calais-Fréthun and Lille-Europe, with trains to Paris terminating at Gare du Nord. Trains to Belgium terminate at Midi / Zuid station in Brussels. In addition there are limited services from London to Disneyland Paris at Marne-la-Vallée – Chessy, services to southern France as of 1 May 2015 and seasonal services to the Alps in winter. The service is operated by eighteen-coach trains which run at up to 300 kph (186 mph) on a network of high-speed lines. The French and Belgian parts of the network are shared with Paris–Brussels Thalys services and also with TGV trains. In the United Kingdom the two-stage Channel Tunnel Rail Link project was completed on 14 November 2007 and renamed High Speed 1 when the London terminus of Eurostar transferred from Waterloo International to St Pancras International.
(Wikipedia).