Borgarnes is a charming little town and a pleasant Icelandic stop when leaving Reykjavik and heading north.
I stopped off in Borganes on almost all of my visits, either to explore the area or just to drink a coffee. During my first stay, I even spent the night there. The small town is located opposite the Borgarfjörður fjord and is a good walk halfway between Snaefellsnes and the Golden Circle.
When you're in Borgarnes, I recommend visiting the Settlement Centre which tells the story of the Icelandic Sagas and of the country's first inhabitants: the Vikings. It's a modern museum with interactive features which help us to immerse ourselves in the early centuries of the country's history.
The centre also houses a very good restaurant and I have fond memories of my meals there.
Finally, you must visit the house of Skalla-Grímr, an important figure in the Sagas who still stands elegantly just outside the town centre.