Brazil is home not only to much of the Amazon rainforest but also to the largest tropical wetland in the world. The Pantanal region covers more than 70,000 square miles in three countries — Brazil, Bolivia, and Paraguay — and contains both national park land and areas protected as UNESCO World Heritage Sites. The Pantanal region has the highest concentration of wildlife in South America.

Bangkok is home to a massive network of waterways that inspire the city’s nickname, the “Venice of the East.” The city’s first canals — known as “khlongs” — were primarily dug as protective moats, including for Rattanakosin Island, upon which King Rama I built the Grand Palace in the 18th century. Later, they were used for irrigation, drainage, and transportation.

Reservoirs are artificial lakes that store water, and are typically built behind dams. The largest reservoir in the United States is Lake Mead, which was formed in 1939 by the construction of the Hoover Dam on the Colorado River. The lake, which lies on the border of Nevada and Arizona, provides 90% of the water used in southern Nevada, including the city Las Vegas.

Deltas are wetlands that are formed by rivers as they empty their water and sediment into another body of water, such as an ocean. The world’s largest delta, the Ganges Delta, lies off the coast of Bangladesh and India along the Bay of Bengal. The 200-mile-wide delta plain is created by the confluence of three major rivers: the Ganges, the Brahmaputra, and the Meghna.

A tarn is a small mountain lake that forms in bowl-shaped valleys carved out by glaciers, known as cirques. Once the glacier has melted away, rainwater or river water flows into the depression left by the glacier, creating a tarn (also known as a rock-basin lake). The term "tarn" is derived from an Old Norse term meaning "pond."

Streams or creek beds that are typically dry but fill up after heavy rainfall are called “arroyos,” which is Spanish for “dry streams.” Arroyos are typically seasonal and can be natural or human-made. They are very common in the American Southwest because of the arid climate, with long dry spells and subsequent rainy seasons. The Arroyo Seco and the Los Angeles River in Southern California are examples of prominent arroyos.

Vernal pools are seasonal wetland habitats that fill up in the spring by rain and snowmelt and dry up during the summer. Their temporary dryness distinguishes them from other types of permanent wetlands like swamps, marshes, and bogs. The word “vernal” itself is a clue to this wetland’s name — it means “relating to the spring,” as in the vernal equinox, or spring equinox.

Pronounced “seh-no-tay,” a cenote is a cave that contains a sinkhole of deep water that is fed from a current of subterranean rivers and rainwater. Mexico’s Yucatan peninsula is famous for its abundance of cenotes, part of the region’s vast cave system. The term comes from the ancient Mayans, who called these sinkholes dz’onot, which translates to “cavern with water.”

An oxbow lake forms when a river meanders and finds a new (usually shorter) route. This causes part of the river to eventually be cut off from the rest, forming a small, curved lake. Oxbow lakes are stillwater lakes, meaning that water does not flow to or from them anymore. They are often temporary, usually becoming swamps or bogs before drying up completely.

China is home to the oldest and longest canal in the world. Construction on the Beijing-Hangzhou Grand Canal began in the fifth century BCE and continued on and off for hundreds of years, until it connected two of China's most important waterways, the Yellow and Yangtze Rivers. Still in use today, the canal spans more than 1,100 miles and is classified as a UNESCO World Heritage Site.

A lagoon is a shallow body of water (typically salt water), protected by a sandbar or coral reef, that opens to a larger body of water like an ocean. Lagoons are commonly seen in the islands of the South Pacific. The island of Bora Bora boasts one of the most-visited lagoons in the world; its shallow waters are bordered by coral reefs and sandbars.

Puget Sound is a relatively small inlet of the Pacific Ocean that stretches into the upper corner of Washington in the Pacific Northwest. The body of water, which is part of the Salish Sea, provides water access to major cities, such as Seattle, Tacoma, and Olympia. During its flow inland, Puget Sound meets 19 different river basins, making it one of the largest estuaries in the country.

A cove is a small bay or inlet with a sheltered entrance. Coves can form off of oceans, rivers, bays, lakes, and lagoons. Pictured here is Lulworth Cove, located in Dorset, on the southern coast of England, just off of the English Channel. It is part of the Jurassic Coast, a 10-million-year-old section of coastline that is known for its fossils.

Norway’s many fjords were created by glaciers that moved through the area during the last ice age. These remarkable bodies of water are surrounded by jagged cliffs and scenic waterfalls, and have become an important part of the country’s tourism industry. Sognefjorden, Norway’s most famous fjord, stretches inland for 100 miles.

A gulf is a portion of the ocean that penetrates land. It is similar to a bay but usually much larger. The Gulf of Mexico is the largest in the world, boasting 3,100 miles of coastline in Mexico, Florida, and Cuba. It is connected to two major bodies of water: the Atlantic Ocean (via the Straits of Florida) and the Caribbean Sea (via the Yucatan Channel).

"Billabong" comes from the word "bilabang" from the Wiradjuri language of the Aboriginal Wiradhuric tribe, who live in New South Wales, Australia. Though the actual translation of "billabong" means "watercourse that only runs after rain," Australians commonly use the term to describe any large body of water.

A bight is a long, gradual bend in a coastline that forms a large, open bay. Bights can be found all over the world, but some of the most well-known are the Southern California Bight, which runs from Point Conception near Santa Barbara to San Diego, and the Great Australian Bight, which covers much of the continent's southern coast.

When a freshwater river empties into an ocean, it creates a brackish area (where fresh water and salt water combine) called an estuary. Estuaries are sometimes named as a bay or a sound, depending on their size. For example, Washington state's Puget Sound is an estuary whose coastline is dotted with rivers and streams that empty fresh water into the icy waters of the northern Pacific Ocean.

Scotland is home to over 31,000 freshwater lochs, or lakes, and its coasts are dotted with saltwater lochs that connect to the sea. This is also where the country’s legendary Loch Ness Monster gets its name. A pillar of Scottish folklore, the monster allegedly resides in Loch Ness, one of Scotland’s largest lakes, located near Inverness.

Straits typically connect two seas or oceans and are crucial to world trade and transportation. One of the most important straits in the world, the Strait of Gibraltar, connects the Atlantic Ocean to the Mediterranean Sea. Straits can also connect smaller bodies of water; the Golden Gate Strait, for example, connects San Francisco Bay to the Pacific Ocean.