One of the only ways to get to Aguas Calientes (the gateway city to Machu Picchu) is to take a 3.5hr train ride alongside the Urubamba River through the Sacred Valley. Definitely take this ride during the day... the views are gorgeous!
Another side of Iceland! Much of south Iceland is green and lush but there is a large expanse of black sand and gravel which is Sólheimasandur. It is actually a glacial outwash plain - when eruptions happen under the nearby glacier the flood water rushes across this land towards the sea.