Mawrth Vallis («Mawrth» is Welsh for Mars) is a 370 mile (600 km) long, 1.2 mile (2 km) deep ravine along the boundary that separates the southern highlands and northern lowlands of Mars. (gizmodo.com)
The dark regions make up more than 10 million square kilometres of the Martian northern lowlands, but their composition wasn't clear. (newscientist.com)
Costa Rica's most active volcano until 2010, the Arenal Volcano soars above the fertile northern lowlands. (reservaconchal.com)