(Travel + Leisure) -- The hum of the single-engine Cessna fills your ears as you ascend above the Peruvian high desert. Below you, flat expanses of dry, brown earth extend in every direction, punctuated only by twisting dry riverbeds ... a lifeless landscape. Then the plane banks, and over the intercom the pilot directs you to look at what appear to be just another set of curving, squiggly lines.
Visitors to Australia can experience the brilliant colors of the Great Barrier Reef from a floatplane and land on the water among the Whitsunday Islands.
But then, as you watch, the lines start to come to life, to form a definitive shape, with a spread-finned tail at one end, a gaping mouth at the other, and an eye in the middle, staring up at you: it's a giant line drawing of a whale, carved right into the landscape.
An aerial tour is the only way to fully appreciate Peru's mysterious geoglyphs, known as the Nazca lines; the 2,000-year-old depictions of animals and geometric figures can be miles long -- much too immense to be seen from the ground. But though these earth-etchings are some of the most dramatic sights you'll ever see from the air, there's plenty of other scenery around the world best viewed from on high.
Most anyone who's spent an hour playing with Google Earth already knows the fascination of observing places from above. When seen from a bird's-eye perspective, even familiar land- and cityscapes become completely new, with colors, patterns, and geographical features you'd never known existed until you hovered above them. Travel + Leisure: See a slideshow of the world's top aerial tours
So it makes sense that aerial tours -- otherwise known as "flightseeing" trips --have become more popular and more specialized over the past few years. Many operators, such as the Wasilla-based Sky Trekking Alaska, have broadened their offerings considerably as customer enthusiasm has grown.
"The interest in seeing Alaska from the air has now evolved into trips that ... include camping in national parks, visiting remote native villages, and enjoying bed and breakfast accommodations" over multiday flights, says Sky Trekking Alaska spokesperson Heather R. S. Oberholtzer. Most recently, the outfit has started offering Iditarod flight tours, which allow guests to track the famous dogsled race from above.
Today's aerial tours run the gamut -- taking in all kinds of scenery from a variety of airborne vehicles. Flightseeing enthusiasts can choose to take in spectacular landscapes -- like the Grand Canyon or New England hillsides carpeted in fall foliage -- via biplane or single-engine craft; they can also check out wildlife -- like New Zealand whales or Tanzanian zebra herds -- via helicopter or hot-air balloon. They can even hover above hectic cityscapes -- like Tokyo's famous neon-studded skyscrapers -- in a zeppelin.
Planning ahead is important when booking an aerial tour. Some seasonal conditions -- like winter snowfall and autumn's changing leaves -- are no-brainers, but there are other things to take into consideration too. Some regions have their own specific meteorological issues -- like the dust that tends to hang in the air during the midday heat in the Nazca Desert, or the mini-monsoons that hit almost every summer afternoon in Australia's tropical Whitsunday Islands.
Flightseeing trips that involve wildlife viewing can be harder to predict; they often involve flying over the right place at the right time. But since there are some animal routines that are well established -- like the migration of wildebeest herds across the Serengeti every summer and fall, and the feeding patterns of sperm whales off New Zealand's Kaikoura coast -- it's wise to talk to a tour operator about the best times to fly.
John MacPhail of Wings Over Whales, an aerial whale-watching tour based in Kaikoura, confirms this. Though "it's not possible to predict when certain kinds of whales will be around," MacPhail says -- referring to blues, fins, humpbacks, and orcas -- "sperm whales feed here all year round." So, even on a not especially lucky sighting day, his tour participants almost always go home with full camera memory cards -- and wonderful memories. Travel + Leisure: Top aerial tours
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