Reykjavik is the capital city of Iceland. It is perhaps best known for its thermal spas, with Blue Lagoon being one of the best known. The Northern Lights are visible from the city, with the best time for viewing being between September and April. The National Museum gives an insight into the Viking heritage of the country. Flights to Keflavik International Airport are available with Iceland Express from London Stansted and with Icelandair from London Heathrow.