40km away from Reykjavik in the East following road n°1, there’s a small town called Hveragerði. It’s pretty famous for its hot springs coming from the close by volcano Hengill and uses this resources for powering up all the greenhouses of the town. The town is known for that. There are about 2400 peoples living here and it’s an interesting place to come have a coffee in one of the greenhouses or enjoying some of Hveragerðis many nice restaurants. You can find Restaurants which cook with the geothermal heat. Most popular is having a walk in the hot spring valley Reykjadalur, find the point about Reykjadalur and all the information you need on the map.
Fun fact: There’s no graveyard here, since the earth is so warm, burying bodies would literally cook them.