The ocean is quite literally a sea of endless wonders. With its waters coving over three-fourths of our planet, the ocean seems to go on for an eternity in all directions. Looking out into the horizon reveals waters that never end which is intimidating enough. What’s even more daunting is seeing and understanding the true depths of the ocean. It stretches so far down that we have never come close to exploring even a fraction of its deep waters. In fact, we have rarely seen the ocean’s floor beds, but when we have, it has revealed some of the most incredible discoveries one can imagine.

With humans always looking to find and explore every inch of our planet, we have voyaged countless miles of oceanic waters and in the process have left behind a great deal of our past. Some of these artifacts date back a century ago and others go back thousands of years, revealing the incredible past of our existence. In the last century, our ability to explore has improved tenfold with so many recent discoveries, both human and not human, including some of the most baffling maritime wildlife.

Here are seventeen examples of the most amazing underwater discoveries and eight strange sea creatures living at the bottom of the ocean!

25 incredible DISCOVERY: River at the Bottom of the Black Sea

It may be hard to visualize, but it is entirely possible for an ocean to contain a river. It’s a difficult concept to grasp, but it’s quite literally the same as any river one would see on land.

The Black Sea contains a river at the bottom of its bed, full with trees, leaves, river banks, waterfalls, sedimentary and flowing waters. The river is exceptional considering it would be the sixth largest in the world if it met the official definition.

24 STRANGE SEA CREATURE: Sarcastic Fringehead

Although the sarcastic fringehead has been found on the surface of the ocean’s waters, they tend to remain in depths going down several hundred feet. This territorial fish is known for its very strange appearance with its large mouth being its most prominent feature.

Although they only grow to about a foot long, their mouth, when open, can seem to be as long as the body of the fish itself, giving it an odd, but scary appearance as it looks like something straight out of a sci-fi movie.

23 incredible DISCOVERY: Mariana Trench

For many, the fear of dark waters can be overwhelming because of the idea of not knowing what is down there. There is no place in the world where this fear is more palpable than the Mariana Trench. Known as the deepest point on the planet, this trough in the Pacific Ocean reaches down well over 36,000 feet!

To put that in perspective, if the tallest mountain in the world, Mount Everest, was sitting at the bottom of the Mariana Trench, it would still come up well over one mile short of the ocean’s surface! This is where the ocean’s depth and size become all too real.

22 STRANGE SEA CREATURE: Frilled Shark

Although not the largest species of shark around, the frilled shark is just as intimidating. Known for its eel-like appearance, this shark can not only grow to nearly seven feet long, but can hunt prey in the dark with expert precision.

Don’t expect to see this shark anywhere near the beach though, as they are often found in the darkest parts of the ocean, living in depths thousands of feet below the surface, with some known cases of them going as low as 5,150 feet, nearly a mile down!

21 incredible DISCOVERY: Galleon San Jose

Considered quite possibly the most financially valuable discovery in history, the Galleon San Jose shipwreck off the coast of Colombia near the city of Cartagena, was estimated to be worth about $17 billion!

This Spanish ship sank during battle at the turn of the 17th century and was carrying millions of gold and silver coins along with emeralds. There has been a nearly four decades long battle between the founders of the ship and the Colombian government over the rightful owner of the treasures.

20 incredible DISCOVERY: Ice Finger of Death

Brinicles, which are better known for their common term, the ice finger of death, are incredible natural phenomena that are found at the bottom of the ocean. Caused by a freezing process involving the ocean’s salt only underneath giant blocks of ice floating at sea, brinicles get their more popular name from their intimidating appearance.

Very rarely ever captured on camera because of the specific conditions needed for this phenomenon to occur, the ice finger of death looks like a water tornado made up of ice, which actually freezes the water around it as the funnel spins and picks up water creatures in its path.

19 STRANGE SEA CREATURE: Giant Squid

Although the giant squid is a well-known underwater creature which has been popularized in film many times, it is actually one of the most elusive sea specimens in the world. It wasn’t until the turn of this century in 2001 that humans saw the giant squid for the first time and only a few years after that when it was finally photographed, making it one of the most elusive on the planet.

The giant squid has long been known to exist, but capturing it on film has taken scientists extensive time and voyages to the deepest parts of the ocean where life is difficult to sustain.

The giant squid can reach total lengths of 43 feet long including its tentacles, making this sea creature absolutely incredible, but intimidating in its own right.

18 incredible DISCOVERY: Lord Krishna’s Lost City

Located off the coast of India, the city of Dwarka, also known as the Lost City of Lord Krishna is one of the most researched and documented underwater sites in the world. Archaeologists believe the city, before it submerged entirely underwater dates back over nine thousand years and was one of the busiest ports in the country at the time.

The city, which is still underwater, has several of its stone structures still intact, along with a grid of streets that were once used by its people.

17 incredible DISCOVERY: Uluburun Shipwreck

Scientists believe this shipwreck dates back to 1305 BC making it one of the most intact discoveries for a wreck of this age. Found off the coast of Turkey in the Mediterranean Sea, the Uluburun wreck was believed to be carrying cargo for a variety of reasons because of the extensive gifts and items found at the bottom of the ocean floor along with the vessel.

Jewelry, gold and silver were found along with copper, clay jars, elephant and hippo tusks, ostrich eggs, pottery, lamps, rare rocks, instruments and what is believed to be the golden seal of Nefertiti. The findings from this ship wreckage make for an incredible discovery that tells a great story dating back to the beginnings of our civilization.

16 STRANGE SEA CREATURE: Black Dragonfish

The black dragonfish has a scientific designation too difficult to pronounce, but it is truly one of the most intimidating creatures found in the sea. Commonly known for migrating to depths past 1,600 feet, their pitch black color blends in with the dark waters they live in.

The black dragonfish’s appearance is the thing of nightmares as they have canine-like teeth and resemble a black eel with large eyes and are bioluminescent, giving off a light when they desire.

15 incredible DISCOVERY: Apollo 11 Engines

The engines from the Saturn V rockets of the infamous Apollo 11 missions which have been popularized in books and cinema are one of the more incredible discoveries on our list. Found off the Florida coastal waters over 16,000 feet below the ocean’s surface, these massive rocket engines were truly at the bottom-most depths of the Earth. The rocket engines fell back down to Earth after their launch and the rocket exiting our atmosphere.

Although they were discovered, there has been a long-awaited mission to bring them to the surface which is no small task considering their massive size and the depths at which they sit. It’s difficult to know what conditions they are in after forty years of sitting in salt water under intense water pressures at such deep levels.

14 incredible DISCOVERY: Vasa Shipwreck

Considered an important find by archaeologists in the 1950’s, the Vasa shipwreck helped scientists understand more about naval voyages during the 17th century when sea travel became most prominent. The Vasa was a Swedish warship which set sail in 1628, but only traveled about 1,400 yards before sinking.

Centuries later the wreckage was discovered with most of the ship completely intact including its hull. The artifacts included weapons, clothes, cannons, sails, coins and even the remains of humans!

13 incredible DISCOVERY: Lost Mahabalipuram Pagodas

Another lost city off the coast of India joins our list, but it’s the discovery that is more remarkable than the city itself. The Lost Pagodas was long considered a myth by many because of the lack of scientific evidence of its existence, but in 2004, when the infamous Indian Ocean tsunami hit, taking hundreds of thousands of lives, for a brief moment, when the waters parted, large rock-like structures emerged from the water and were witnessed by many onlookers.

Thereafter, expeditions to find out more led to the discovery of the Lost Mahabalipuram Pagodas in India, making it an incredible discovery in both what it yielded as well as how it was found.

12 incredible DISCOVERY: SS Central America

Known as the Ship of Gold, the SS Central America set sail in 1857 for New York City from Panama with 477 passengers and 101 crew members and nearly ten tons of gold. Shortly after beginning its voyage, only six days after, the SS Central America sunk taking 420 lives with it. The cause of the eventual demise was a hurricane in the Atlantic Ocean right off the coast of the Carolinas where the ship went down, short of its final destination.

The ship’s sinking had a big effect on the conscious of America as the loss of life was significant and the sheer amount of gold that disappeared actually had an impact on the country’s economy.

11 STRANGE SEA CREATURE: Pelican Eel

The pelican eel, which is often referred to as a gulper eel as well, is a deep sea fish that lives at depths where water becomes too dark to see as the sun simply does not reach this far down. The pelican eel gets its name because its mouth resembles that of a pelican due to the enormous size it can open up to when swallowing prey. The mouth can open to such a wide size that it can even get bigger than the eel’s actual body itself, making it not only scary to look at, but dangerous as well.

10 incredible DISCOVERY: Antikythera Mechanism

This artifact gets its name because of the location where it was discovered. This mechanism was found off the coast of the Greek island Antikythera and is believed to be associated with the ancient Greek civilization. The device was found among the wreckage of a ship and experts believe it was designed thousands of years ago by Greek scientists as a mechanism for measuring astrological occurrences as well as a calendar which would have been considered far ahead of its time based on the advanced nature of its accuracy.

9 incredible DISCOVERY: Ancient Roman Medication

Off the coast of Tuscany, Italy, a ship called the Relitto del Pozzino sank over two thousand years ago. The Roman shipping vessel was discovered in the 1980’s and 1990’s by an Italian archeology team and the most incredible discovery wasn’t a treasure or gold.

Inside tin cans which remained sealed for several millennia were pills still perfectly preserved. After intense study, scientists believed that these pills were remnants and insight into ancient medicine used by the Romans, most likely used as eye medication.

8 STRANGE SEA CREATURE: Diving Bell Spider

When we get into the water, our fears are about the deep and oceanic creatures like sharks and strange fish. We never think that spiders are something to worry about when in water, but that’s certainly the case when it comes to the diving bell spider.

It’s the only species of spider in the world that spends almost all of its entire life underwater, only coming up for a second of air once a day or so. The spider’s intimidating appearance is punctuated by its all black color and silver belly, making this one creature you surely don’t want to come by in the water.

7 incredible DISCOVERY: Elongated Skulls

Near the Mexican ruins of an ancient village called Mayapan sits a flooded sinkhole called Sac Uayum. This underwater cave has become somewhat of an urban legend to the Mexican villagers that live near and around it, inciting fear because of its place in their history as an important religious site where sacrifices were once made.

In a recent underwater search of the cavern by experts, the remains of human bones were found throughout the waterbeds, including elongated skulls which scientists were not able to completely understand, only adding to the location’s mystique and fear.

6 incredible DISCOVERY: Underwater New Jersey Locomotives

One of the more eerie discoveries on our list is this inexplicable entry of a locomotive graveyard. Found off the coast of New Jersey, were several fifteen-ton locomotives in incredible condition, nearly one hundred feet below the ocean waters. The trains were built in the 1850’s, making this discovery over a century and a half old with very little explanation for how they ended up in the ocean.

The jarring part of this find is there are no records of the steam engines, but experts believe they were being transported via sea and had to be pushed off ships to prevent it from going down since there is no wreckage of a ship. The locomotives found at the bottom of the ocean floor were standing upright as if ready to take off underwater.