45 minutes by car from Reykjavik. Follow the signs toward Thorlakshofn. There will be a turn-off for Eyrarbakki and Selfoss before you reach Thorlakshofn. If you're coming from the Golden Circle, don't forget to stop off at Kerid Volcanic Crater along the way, which is just before you get to Selfoss. Selfoss is 15 minutes away.

From the airport or the Blue Lagoon, take the road that goes through Grindavik and then follows the coast. It's a lovely drive, in addition to being more direct.