We jumped on an amphibious boat which took us around the lagoon passing by some impressive icebergs. Our guide got a piece of the iceberg and we tasted fresh mountain water. After the tour, we walked up a little hill for better views.
Kirkjubæjarklaustur after which we headed to our Airbnb close by. We had a found a cosy little place by the banks of Tungufljot River, literally in the middle of nowhere.
Þingvellir is most famous for being part of the mid Atlantic fault line between the North American tectonic plate and the Eurasian tectonic plate. The continental drift can be observed here with many fissures and rifts. The Almannagja fault is more than 7km long and the rift valley could 60m wide. The only other place in the world where you can see continents drifting and walk between them is the Great Rift Valley of Eastern Africa.
There is indeed a lot more to do in Iceland. You can encircle the island if you have a week or more, and the North East has a lot to offer. Even in the South West, we haven't covered a lot many activities. There are many thermal lagoons. The most popular ones are the Blue Lagoon which is right next to Rekjavik (it's really a spa resort) and the Secret Lagoon near Gullfoss on the golden circle.Horse riding on Icelandic horses is also very popular. They are meant to be very very docile but sturdy. Whale watching from Rekjavik or the North East (near Dalvik/Hossuvik) is specially popular in summer. The lady on my flight back who worked in both places and told me that the whale watching opportunities in North East in the summer are excellent compared to Rekjavik at any time. Puffins watching tours are also on offer from Rekjavik or Vik. Some companies offer snowmobile tours where they you on a glacier and give you a snowmobile to drive around. There are some manmade ice caves which are nice to see as the ice which is very hard, clear and densely packed, and hence allows you to see through it for a considerable distance. And of course there are volcano tours.