How can I take a bus to the Blue Lagoon from Reykjavik?

To take a bus to the Blue Lagoon from Reykjavik, you can book a tour with a local tour company or use the public bus service called "Strt." The bus route number 55 goes directly from Reykjavik to the Blue Lagoon. You can check the schedule and purchase tickets online or at the bus station in Reykjavik.