4. Þjórsárdalur and Slakki in Laugarás

Driving to Thjorsardalur (Þjórsárdalur), about 100 km from Reykjavik, looking at Hjalparfoss, Stong (the historical farm which was covered with lava from Hekla), Gjain (one of the most beautiful places in Iceland), and swimming in the pool in Thjorsardalur in the middle of nowhere, will make a very nice day.
On the way home: Visiting the animal farm Slakki in the small village Laugarás about an hour drive from Reykjavik.