Despite my affinity for driving, especially long-distance, there are two types of junctions that cause me some degree of apprehension - unprotected left turns, and roundabouts. I think the apprehension about roundabouts simply comes from the fact that there don't seem to be too many in the United States, at least not in my patch of ground, therefore I have limited experience navigating them. I did get a roundabout crash-course during my trips to Iceland; unlike an unprotected left, they are impossible to avoid by simply taking the long way around the block, and after the first ten or so, I realized they weren't all that scary.
However, I can say that I was really happy to not be the one behind the wheel going though the magic roundabout in Hemel Hempstead, which is six roundabouts feeding either out and away, or into each other.
This experience prompted me to do a spot of research on roundabouts, and why they are better at controlling the flow of traffic than intersections with lights. One of the arguments seems to be that, because traffic is forced to slow to a crawl, collisions causing serious damage are rare. I do see the sense in this, since high-speed broadside collisions in traditional intersections are not only common, but can have devastating results. But navigating one of this nature, including understanding the right-of-way rules once inside, wasn't terribly intuitive, and it wasn't just me. When I expressed some confusion on how exactly one gets from one side to the other, my British friend who was driving declared that she was just going to follow the car in front of us, hoping it would get us to the correct exit. Which, thankfully, it did, and we weren't doomed to hours of driving in one slow circle after another until we managed to break free of the traffic vortex.