High Speed 1 is a high-speed rail line in the United Kingdom that connects London to the Channel Tunnel. It was opened in 2007 and allows trains to travel at speeds of up to 300 km/h (186 mph), significantly reducing travel time between London and Paris or Brussels. The line is part of the Eurostar service, which provides international train travel. High Speed 1 runs for about 109 kilometers (68 miles) and includes several key stations, such as St Pancras International in London. This infrastructure enhances connectivity and promotes sustainable travel options across Europe.