High Speed 1 is the high-speed rail line linking London with the Channel Tunnel.
High Speed 1, commonly abbreviated HS1, runs from London St Pancras International to the Channel Tunnel at the Kent coast. It opened in stages, with the complete route entering service in 2007. Eurostar trains use it for international journeys between Britain and continental Europe.
The line was formerly known as the Channel Tunnel Rail Link. It includes purpose-built high-speed infrastructure, tunnels beneath London, and connections to the Channel Tunnel. Passenger trains can reach 300 km/h on much of the route, although the overall journey speed varies with stops and operating conditions.
High Speed 1 is distinct from High Speed 2, a separate British project intended to connect London with cities farther north. It is also not the Channel Tunnel itself: HS1 approaches the tunnel, while the Channel Tunnel carries trains beneath the English Channel.