What is the best route from Heathrow T5 to Euston Station using the underground?

To travel from Heathrow Terminal 5 to Euston Station, several routes are recommended. A common suggestion is to take the Piccadilly Line to Green Park, then transfer to the Victoria Line straight to Euston. Alternatively, you can take the Heathrow Express to Paddington and then a taxi or the Underground to Euston. This journey usually takes about 1 hour and is relatively straightforward. For real-time navigation, using the London Tube app or Google Maps may prove helpful.