There aren't many fjords in this part of the country. The biggest one is Hvalfjordur which now has a tunnel under it that was opened in 1998. It is well worth the extra 50 km drive around it if the weather is good and in the bottom are beautiful hiking trails including one to the highest waterfall in Iceland, Glymur, 218 meters high. Around Reykjavik there are some smaller fjords but the peninsula itself has almost none.