Eurostar operates its services from St. Pancras station in London and terminate at Paris Gare du Nord station in Paris or Brussels Midi station in Brussels. It travels via Channel Tunnel to cross English Channel. Eurostar trains also provide direct trains to Avignon international station in France for a specific period of year.
Eurostar connects around 100 destinations in Europe in cooperation with other high speed trains like Thalys, TGV, ICE and many others. You can travel anywhere in France by Thalys train after reaching Paris by Eurostar. Tickets for all destinations are available on Eurostar itself. Similar you can travel to Germany or Amsterdam from Paris or Lille.
Here is a route map which can help you to know about destination connected by Eurostar.
Eurostar Route Map
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