Walk in Reynisfjara Beach

Forgetting that Game of Thrones put this view on every fan to do list, it is still absolutely worth the trek if you're on the Southern Road. 

Reynisfjara Beach is the South Coast of Iceland's most famous black sand beach. Its beautiful black sand, powerful waves and the nearby maritime stacks of Reynisdrangar make Reynisfjara a unique place to visit. While the sands found on most of the world's beaches are colored white or golden, the specifics of their formation make black sand beaches much rarer. Sand is created by eroding rocks into small fragments (by definition, a beach is merely a collection of many small stones). 

According to the folktale, these rocks are the remains of two trolls who tried to tow a ship to land, but were caught by daylight and turned to stone. The black sandy beach is treacherous if you do not take reasonable precautions, and many have drowned there. It is well signposted to alert you. Caves formed by row upon row of tall basalt columns are a highlight, and everyone clamors up on them for photos. Parking can be a challenge at peak times but it is free, and there are bathrooms and a coffee shop if you want to enjoy a bevy on the sand while puffins cliff dive above your head. Go at sunset and see the glistening light hit wet black sand and sea birds swarming to nest.