There is a school next to the cache and a lot of guests from all over the world are jumping around the hiding-place... So be careful and take your acting skills with you! ;)
By the way you won't be able to find the cache without being seen by Dagur and Nott (Icelandic for day and night)! But don't be afraid, they are very kind and just ask you for a cuddle! :)
And don't worry, you are allowed to enter the garden of the guesthouse!
After you found the cache you could walk down to the coast and enjoy the wonderful view and the sea!