We are traveling to Iceland this July and will not have a car. I want to go to the Blue Lagoon but my husband and daughter are not interested. I'd like to find some more adventurous activity that they could do on a day tour from Reykajavik while I'm relaxing at the Blue Lagoon. We have ruled out snorkeling at Silfa and glacier hiking (for various reasons). What would you suggest? Thanks for your help!