//
Iceland is very favorably located within the aurora belt and chances of observing the beautiful atmospheric phenomenon are rather high between September and March even in the vicinity of the capital; in summer months lack of darkness is the limiting factor. To boost your viewing chances commons sense suggests escaping from the city lights. Due to the tree-free character of the Icelandic countryside only clouds can obstruct your view then. A valuable tool for getting prepared for your observation is the local meteorological office's Aurora site, forecasting both auroral activity and cloudiness. If you don't have a car available, there are plenty of agencies organising short trips who pick you up at your hotel.
The Pond
A small lake in the centre of the city where young and old often gather to feed the ducks. The Icelandic name, Tjörnin, literally means "The Pond". Tjörnin is mostly surrounded by a park called Hljómskálagarðurinn (Music Pavilion Park) which gets very popular in good weather. The southern end of Tjörnin links it to the Vatnsmýri swamp, a small bird reserve with paths open to the public except during egg hatching season. Built into Tjörnin on the northern side is Reykjavík City Hall.
A small park (or square, depending on definitions) in the heart of Reykjavík. It's many locals' favorite place to spend sunny days, either at one of the cafés lining the north of the square or simply having a picnic on the grass. The parliament and the national cathedral both stand by Austurvöllur.
Klambratún is a park just east of the city centre on an area which remained farmland while the city was built up around it. The area was later converted into one of the largest public parks in the city and often hosts various events. One of the houses of the Reykjavík Art Museum, Kjarvalsstaðir, is inside the park.
Grasagarður Reykavíkur
The Reykjavík Botanical Gardens are not large, but they're nice for a short stroll and a good place to see some of the plants that grow in Iceland.
Viðey is a large island in Kollafjörður, the fjord to the north of Reykjavík. It used to be inhabited, and in the early 20th century it had a small fishing village. Nobody lives there anymore apart from the birds, but it's a popular way to get away from the city without leaving it. During the summer, a café is operated in one of the houses on the island. The building was built for Skúli Magnússon, an 18th-century politician often called "the founder of Reykjavík" and designed by the same man as the royal palace in Copenhagen - although it is not quite of the same scale. Among its more modern architecture, Viðey is home to the Imagine Peace Tower by Yoko Ono (see below). To get to Viðey you must take a ferry from Sundahöfn, some distance from central Reykjavík (on bus route 5). The schedule and prices can be found here.
At the far western end of the peninsula on which Reykjavík sits there is a small island. This island, called Grótta, is connected to the mainland on low tides and open to the public most of the year (closed May 1-Jul 15). Just make sure you don't get stuck on the island when the tide comes in!