For the thinking Icelander, of which there are few, Thingvellir National Park is the most sacred place in the whole country. It should be for you too.
Not only is Thingvellir home to the oldest Parliament in the world, not only can you hop effortlessly between the European and American tectonic plates, not only is it a World Heritage Site but also it is one of the most beautiful landscapes in the Northern hemisphere. To list all the wonders of this place would practically take forever and since we are but mere mortals any effort will always be half-baked. We will cut it short.
This is home to Thingvellir lake, Iceland´s largest lake, where sport-fishing is allowed in summertime. Wild berries grow here abundantly and are ripe for picking late August each year. Hengill geothermal area can be seen from afar by the steam rising from the geothermal plants and is interesting to see and explore if you do not mind the sulfuric smells.
We have yet to mention Oxaráfoss, Axe River Fall, where people were executed in the past for crimes and misdemeanors. By the same lovely river a group of wise men gathered in 903 and founded a pretty democratic Parliament long before foreigners even thought of the idea. The name Thingvellir is Icelandic for a meeting field. This is also the place where Icelanders formally declared independence from the Danes. Although, it must be said, we did so while the Danes were occupied by Nazi Germany. Very convenient indeed.
Yet, we have not mentioned what lies beneath. Equally astounding world is to be found below ground in an extensive underground cave system. Cave diving has become a recent phenomenon here and a few dive companies operate from Silfra pond. This also is unmissable whilst travelling here.
There are cons too for those interested. Services within the park range from bad to non-existent although this is getting slightly better. There is but one service station here and crowds form there easily when buses arrive en-masse each day. No hotels or guesthouses are found here but if you know local millionaires they could possibly let you rent one of a handful of cottages found by the lake. It is possible to camp here in certain spots and is highly recommended but seek permission beforehand.
View Thingvellir Iceland in a larger map