Saguaro cacti, Ironwood National Monument, Arizona

© Jack Dykinga/Minden Picture

Ironwood Forest National Monument, Arizona, USA

Massive succulents against a mountainous backdrop, underneath the sun-kissed sky—it's prickly perfection. Pictured here are saguaro (pronounced 'sah-wah-roh') cacti at Arizona's Ironwood Forest National Monument in the Sonoran Desert of North America. Even if you haven't seen one in person, when you hear the word cactus, you're probably thinking of saguaro—tall, green, cylindrical, with arms pointing upward. Though they are slow growers, these plants have been known to live over 200 years and reach enormous heights, with one setting the record at 23.8 metres. Another saguaro cactus, known as 'Grandaddy,' survived in the sweltering desert for about 300 years, eventually succumbing to old age in the early 1990s. Cacti may not be for everyone, but they tend to grow on you (figuratively, of course)!