This long, rewarding day trip traces Icelands dramatic south coast and packs in more scenery than seems possible in a single outing. You will walk behind the tumbling curtain of Seljalandsfoss, stand beneath the mighty Skogafoss, and tread the black volcanic sand at Reynisfjara, where basalt columns rise like a pipe organ and puffins wheel overhead in summer. A glacier viewpoint rounds off the day. Bring a waterproof jacket for the waterfall spray and keep well back from the sneaker waves at Reynisfjara, which can be genuinely dangerous.