Mono Lake, California

“In the middle distance there rests upon the desert plain what appears to be a wide sheet of burnished metal, so even and brilliant is its surface. It is Lake Mono.” So wrote Israel C. Russell in the “Quaternary History of the Mono Valley” in 1889. Much of the ancient saline lake hasn’t changed. Mono Lake, which covers more than 70 square miles, has no fish. It is believed the lake could be 1 million to 3 million years old, and it is among the oldest lakes in North America. One thing that has changed here as the landscape makes the transition from the Sierra Nevada Mountains to the Great Basin Desert is the appearance of tufa, unusual rock formations that crowd the shore. The tufa towers are limestone and grow underwater; they are exposed because the lake grew more shallow when water diversions started in 1941.

Goblin Valley State Park, Utah

Goblins? Hoodoos? The names fit these mysterious-looking rock formations in Goblin Valley State Park in southern Utah and surrounded on three sides by Canyonlands and Capitol Reef national parks and Glen Canyon National Recreation Area. Sandstone erosion made the shapes; the small, spherical shapes of the goblins combine with the hoodoos, rock pinnacles in the shape of mushrooms, to give the landscape an eerie edge.

Zlatni Rat, Croatia

The sand of Zlatni Rat (Golden Cape) beach in Croatia is continually on the move, as wind, tides and currents sculpt the beach into ever-varying shapes. (Don’t worry — these changes are subtle and sunbathers are not washed away). The beach is a sand spit extending from a promontory near Bol, on the southern coast of the island of Brac. The same winds that subtly change the shape of the spit are the fuel for windsurfing adventures.

Pamukkale, Turkey

Cotton Castle, Pamukkale’s translated name, is a wildly popular tourist site. Seventeen hot-water springs in the area spill out water in temperatures ranging from 95 degrees to 212 degrees, which contains a high concentration of calcium bicarbonate. The water flows off a cliff, cools and hardens into calcium deposits that form terraces, as white as cotton and bright enough to be easily seen from the town of Denizli, which is on the opposite side of the valley, 12 miles away. These terraces, which continue to grow, hold pools of water. Soakers are welcome; shoes are not, to protect the deposits.

Racetrack Playa, California

Even NASA cannot explain it. It’s best to gaze in wonder at the sliding rocks on this dry lake bed in Death Valley National Park. Racetrack Playa is almost completely flat, 2.5 miles from north to south and 1.25 miles from east to west, and covered with cracked mud. The rocks, some weighing hundreds of pounds, slide across the sediment, leaving furrows in their wakes, but no one has actually witnessed it. Is it the wind? Something to do with ice? Will it ever be explained?

Middle East Desert Floor Drawings

The secrets of these stone structures are only now being unraveled, probably because it is nearly impossible to get the entire picture at ground level. But with views from airplanes and satellites, archaeologists have discovered thousands of these “floor drawings” of stones in Syria, Jordan and Saudi Arabia. The wheels measure from 82 feet to 230 feet across and could be at least 2,000 years old; other stone structures are far older. What were they used for? Did they carry special meaning? That is still secret.