Silfra is a rift formed in 1789, due to the movements of the two tectonic plates that frame Þingvellir National Park in Iceland. The North American and Eurasian plates, which run all the way through Iceland, separate at about 2 centimeters per year, and as they do, they tear open fissures in the land between them.
Scuba diving and snorkeling in Silfra is popular because of its clear water and location within the continental rift. There are three main dive sites: Silfra Hall, Silfra Cathedral and Silfra Lagoon. The Cathedral is a 100 metres (330 ft) long fissure with visibility almost from end to end. Shallow at the entry points and at the ends of the fissure, Silfra descends to a maximum depth of 63 metres (207 ft) but diving to this depth is seldom done as it requires technical diving skills. The water temperature is between 2–4 °C (36–39 °F) but can be comfortably dived using a dry suit.
Jellyfish Lake is a marine lake located on Eil Malk island in Palau. The lake is connected to the sea via three tunnels that lie near the surface. The tunnels channel tidal water in and out of the lake. The millions of golden jellyfish found in the lake, which represent a unique subspecies of Mastigias papua etpisoni jellies. spend much of their lives on the move during a daily migration that follows the sun’s arc across the sky. Jellyfish Lake is one of the best places in the world to enjoy the experience of swimming among a sea of jellies.
Ik Kil, located in the northern center of the Yucatán Peninsula, Mexico, is a deep natural sink hole open to the sky, that formed by the collapse of a cave. With vines and ferns extending downward into the sinkhole it is a place of unbelievable natural beauty. Also, there is a carved stairway down to a swimming platform. Cenote Ik Kil was considered sacred by the Mayans who used the site as a location for human sacrifice to their rain god.
Underwater rivers are formed when the fresh top water meets the exposed salty groundwater. The different density levels in the two waters causes them to layer. Undersea rivers are similar to the rivers we see on land. They have banks on either side, They carve valleys into the sea floor and follow meandering paths. These rivers were unknown until the 1980s, when sonar mapping of the seafloor began to reveal them. Angelita in Yucatan, Mexico, looks like any ordinary swimming hole. It’s not until you dive almost 100 feet that the underwater river becomes exposed.
Rainforest Expedition’s Troy Alexander spotted the bizarre maypole-in-miniature in the Southern Peruvian Amazon. Alexander posted a photograph of his discovery to /r/whatsthisbug, a subreddit devoted to identifying insects and their handiwork.
Multnomah Falls is located on Multnomah Creek in Oregon, US. Spanning two tiers on basalt cliffs, it is the tallest waterfall in the state of Oregon at 620 ft (189 m) in height. The falls drops in two major steps, split into an upper falls and a lower falls. The two drops are due to a zone of more easily eroded basalt at the base of the upper falls. Underground springs from Larch Mountain are the year-round source of water for the waterfall, augmented by spring runoff from the mountain’s snowpack and rainwater during the other seasons. According to legend from the Multnomah tribe (from whom the falls take their name), the waterfall was formed after a young woman sacrificed herself to the Great Spirit to save Multnomah village from a plague by jumping from the cliff. After her death, water began to flow from above the cliff, creating the waterfall. Multnomah Falls is the most visited natural recreation site in the Pacific Northwest with more than 2 million stopping by each year.
The Sargasso Sea is a region of the North Atlantic Ocean bounded by four currents that swirl around the Bermuda forming a vast whirlpool called the North Atlantic gyre. Unlike all other regions called seas, it has no land boundaries. It is distinguished from other parts of the Atlantic Ocean by its characteristic brown Sargassum seaweed and often calm blue water. The sargassum originates in the nutrient-rich zones close to the coast of the Americas, particularly in the Gulf of Mexico. All of the currents deposit the marine plants which they are carrying into this sea, yet the ocean water in the Sargasso Sea is distinctive for its deep blue color and exceptional clarity. It is also a body of water that has captured the public imagination, and so is seen in a wide variety of literary and artistic works and in popular culture. The Sargasso Sea is frequently (but erroneously) depicted in fiction as a dangerous area where ships are mired in weed for centuries, unable to escape.
Romer is a land-locked freshwater fjord at the northern end of King Frederick VIII Land, near Greenland’s northeastern coast. The Lake is famous for its impressive Elephant Foot Glacier, a wide piedmont glacier with a strikingly shaped 5.4 kilometers (3 mi) wide terminal lobe flowing into the lake from the SE in its central part.
Hamilton Pool Preserve is a natural pool that was created when the dome of an underground river collapsed due to massive erosion thousands of years ago. The pool is located about 23 miles (37 km) west of Austin, Texas. The pool is surrounded by large slabs of limestone that rest by the water’s edge. Large stalactites grow from the ceiling high above. The ceiling and surrounding cliffs of the grotto are home to moss, maidenhair fern and cliff swallows. The Ashe juniper (cedar) uplands of the preserve are home to the endangered golden-cheeked warbler.
info source: wikipedia
Iturup is the largest island in Russia’s southern Kurils, located directly to the north of Hokkaido, Japan. Iturup consists of volcanic massifs and mountain ridges. The mountains are covered with birch and Siberian Dwarf Pine scrub, herbaceous flowers or bare rocks. The shores of the island are high and abrupt and is marked by white pumice cliffs and black hexagonal pillars.