You will find black beaches all over Iceland. But in the south they are packed with tourists and in the east you can have a beach like this one all to yourself if you are lucky.
From the parking lot it is just a short walk down to the beach.
Always be aware that the sea around Iceland can be very unpredictable. The black sand beaches in the south are known for sneaker waves (waves that sneak up on you because they are a lot bigger than he other waves). So always be careful when visiting a beach like this one.