Garður Lighthouse and its nice red stripes offers very nice photographic opportunities.
Photo Tips: I like the frontal view from the bridge with its symmetry. You can use ultra wide lenses right on the bridge, or back a bit for slightly different compositions with rather normal lenses. However, there are other great possibilities from either side of the Lighthouse.
Getting there: You can park right next to the Lighthouse. This is a great spot to visit right from the airport, as its only about 10 minutes drive. Might be great before a night flight home...
My first ever picture with a fisheye, the Canon 15mm, a borrowed lens. It's much fun, but if you miss the horizon it gets so unbelievably distorted...