Grotta Lighthouse is located at the very border of the city of Reykjavik and is a major sightseeing location - it is popular for both observing the Northern Lights, and a casual walk away from the hustle and bustle of the city. The lighthouse is directly accessible only at low tide, and the rest of the time, you can only enjoy it from a distance. It is a popular bird-watching spot since several species are nesting in the area.