The world is a complex and dynamic place. And learning these remarkable facts may mean you never look at this wonderful planet in the same way again.

Geography is the scientific study of Earthly phenomena. It examines both natural and human processes, and their impact on each other and the planet. Geography tries to simplify a complex entanglement of physical and social systems to determine how exactly the world ticks. But this planet is a complex place. And as the following 20 facts demonstrate, it never ceases to surprise.

20. The Diomede Islands cover a time difference of 21 hours

Located in the Bering Strait, the Diomede Islands consist of two desolate isles just over two miles apart. However, their time difference is 21 hours. This is because they are divided by the International Date Line, an imaginary border which demarcates the change of one day to the next. Big Diomede, which is also known as Tomorrow Island, is part of the Churkotka Autonomous Okrug in Russia. Little Diomede, or Yesterday Island, is part of Alaska in the United States.

19. The Mississippi River “flowed backwards during the creation of Reelfoot Lake in Tennessee”

In 1811 and 1812, three devastating earthquakes rocked the area of New Madrid in Missouri, generating aftershocks that could be felt in Canada. The subsidence they caused transformed the local landscape and created Reelfoot Lake in Tennessee. Witnesses say they saw the Mississippi flowing backwards at the time of the earthquakes. But modern scientists believe this was merely an illusion caused by seismically generated waves.

18. Point Nemo is the most remote place on Earth

This small, barren island in the South Pacific Ocean is actually pretty special. Point Nemo is the world’s “oceanic pole of inaccessibility” – the point most distant from land. Its name means “No One” in Latin and it is located nearly 1700 miles from the nearest landmass. Point Nemo was the location of “the nightmare corpse-city” of R’lyeh in H.P. Lovecraft’s Call of Cthulhu. The name is also said to have been inspired by Captain Nemo of Jules Verne fame.

Image: Fiona Goodall/Getty Images for Lumix

17. The Pacific Ocean is large enough to fill a hemipshere

The Pacific Ocean is so huge it has antipodal points. This means you can travel in the diametrically opposite direction to the surface of the ocean, pass through the center of the Earth and emerge in the Pacific on the other side. In fact, the Pacific Ocean is so large that it covers its own hemisphere.

16. Mount Chimborazo, not Everest, is the world’s highest mountain

At school you were probably taught that Mount Everest is the highest mountain in the world. This is correct, in terms of its height from sea level. But measuring from the Earth’s center makes Mount Chimborazo, an extinct volcano in the Andes in Ecuador, the world’s highest peak. That’s because Chimborazo is located near the equator. This means it gains extra height from the “equatorial bulge,” which gives the planet its sphere-like shape.

15. The magma under Yellowstone Park could fill 11 Grand Canyons

In 2015 researchers from the University of Utah found that the magma reservoir under Yellowstone National Park was more than four times bigger than previously thought. In fact, there is enough magma there to fill 11 Grand Canyons. The so-called Yellowstone Caldera supervolcano last erupted 640,000 years ago. However, scientists do not believe another eruption is imminent.

14. Canada has an island within a lake, within an island, within a lake, within an island

This nameless place is only four acres in size. The Canadian island sits within a lake. That lake is inside another nameless island, that is inside a bigger lake on Victoria Island, which itself sits in the Canadian Arctic Archipelago. The islet is not the world’s only third-order island, but it is quite possibly its largest.

13. Antarctica is home to the world’s biggest desert

Many believe the Sahara Desert is the world’s largest. But with an area of around 3.5 million square miles, it is only the world’s third biggest. A desert, according to geographers, is a place of extreme temperatures and little humidity. This makes the Antarctic Polar Desert, which covers an area of 5.5 million square miles, the world’s biggest. The second largest is the Arctic Desert with 5.4 million square miles.

12. Kiribati is the only country in the world to span four hemispheres

Kiribati consists of one raised coral island and 32 atolls scattered over 1.3 million square miles of Pacific Ocean. In fact, the islands are divided by both the equator and the 180th meridian. This places the Micronesian state in the northern, southern, eastern and western hemispheres simultaneously.

11. The Sargasso Sea has no coastline

We normally associate coastlines with seas. But the Sargasso Sea in the North Atlantic Ocean is the world’s only exception. It is located within the rotating system of currents which form the Northern Atlantic Subtropical Gyre. The sea is bordered by the Gulf Stream, and the North Atlantic, Canary and the North Atlantic Equatorial currents. It is named after the brown sargassum seaweed which grows there.

10. 90 percent of all humans live in the Northern Hemisphere

A number of factors influence patterns of human settlement and development. These include the relative abundance or scarcity of fresh water, fertile land, amenable temperatures, easily navigable terrain, communications and resources. But the main reason that 90 percent of the planet’s population lives in the Northern Hemisphere is because there is much more habitable land north of the equator.

9. The world’s shortest place name has one letter; the longest has 167

There are several places in Norway and Sweden called Å – an old Norse word for river. Meanwhile, a New Zealand hill long held the record for the longest name. It’s called Taumatawhakatangihangak oauauotamateaturipukaka pikimaungahoronukupokaiwhe nua kitanatahu. But it has now been beaten by Krung thep mahanakhon bovorn ratanakosin mahintharayutthaya mahadilok pop noparatratchathani burirom udomratchanivetmahasathan amornpiman avatarnsathit sakkathattiyavisnukarmprasit. The new record-holder is better known as Bangkok.

8. China falls within a single time zone, despite spanning the equivalent of five

In western China, in some parts of the year, you can watch the sun set at midnight. This is because Beijing Standard Time is the only time zone in China. However, it has not always been so. In 1912 the Republic of China created five zones oriented around the world’s temporal standard, Greenwich Mean Time. In 1949 however, the Communist Party ruled that henceforth there should be one.

7. The Atlantic coast entrance to the Panama Canal lies to the west of the Pacific coast entrance

Since the Atlantic Ocean lies to the east of the Americas and the Pacific Ocean to the west, it seems strange that the Panama Canal’s Atlantic entrance lies to the east of its Pacific entrance. The reason is that Panama is a narrow s-shaped country that runs from west to east. And although the canal unites Pacific and Atlantic Oceans, it runs from north to south.

6. Mexico City sinks 4-6 inches annually

With a population of 21 million, Mexico City is an urban powerhouse. But over the last 60 years, subsidence has caused it to sink 32 feet. The cause of this is over-extraction of water resources. The city is in fact built on top of a lake bed. And each year, it extracts around 201 billion gallons of water from the aquifer underneath it, causing the water table to sink by more than three feet a year.

5. Pheasant Island switches countries every six months

Located in the Bidasoa river – which forms an international border between France and Spain – Pheasant Island is a diplomatic curiosity. It changes its national allegiance every six months. Technically, the uninhabited island is held under joint sovereignty by both France and Spain. In effect, administrative responsibility for the island alternates every six months.

4. Travel north, south, east or west from Stamford, Connecticut, and you’ll arrive in New York State

All roads lead to Rome, or should that be New York State? From the city of Stamford in Connecticut, you can travel north, south, east or west and still arrive in New York State. No, it isn’t the work of an unearthly vortex. The reason is due to the quirk of local geography and the peculiar angles of local state lines.

3. The diameter of the moon is shorter than the width of Australia

At 2,485 miles, the diameter of Australia is roughly 385 miles wider than the diameter of the moon. However, cutting the moon in half gives a cross-section with an area of approximately 3,666,000 square miles, whereas the land area of Australia is only 2,970,000 square miles. Thus, Australia may be wider than the moon, but it is not necessarily larger.

2. The Dingo Fence in Australia is longer than the Chinese—Russian border

The Chinese-Russian border runs for 2615 miles but the Dingo Fence in Australia is almost a third longer. It was built in the late 19th century to control rabbit plague, and subsequently changed in 1914 to protect the sheep flocks of southern Queensland against dingoes. It is the longest fence in the world.

1. Some sinkholes are made by humans not nature

Sinkholes are holes in the ground which are created when the land above it collapses. Naturally occurring erosion is usually responsible. However, some sinkholes are created by human activity. For example, some dams contain engineered sinkholes which act as spillways. And in Guatemala, pictured above, a broken drain pipe may have caused a 300-feet-deep sinkhole to form.