Our oceans are full of secrets and, even though they’re part of our planet, there’s so much we do not know about the deep waters of the world. That doesn’t mean we’re not interested! Of course we are! There’s something magical and mystical about ocean life – maybe because we know so little about what lurks underneath. By that, we’re not just talking about marine life, we’re referring to the spectacular ruins of ancient artifacts standing proudly on the ocean floors.

Over the years, archeologists have discovered some wonderful treasures in oceans around the world. Each underwater finding comes with its own fascinating story. But did you know that we’ve actually only explored up to 5 percent of the ocean floor? It makes us wonder how many more marvelous ancient relics could be hiding underneath the world’s waters. Maybe one day, we’ll find out.

Thanks to advancing technology, more underwater discoveries are destined to come. For now, let’s focus on the amazing things that have already been discovered and the intriguing backgrounds of these treasures. From ancient weapons dating back two millennia to Lord Krishna’s Lost City, here are 20 mysterious artifacts found at the deepest darkest corners of the ocean.

20 The Kingdom of Cleopatra

The Kingdom of Cleopatra was lost for 1,600 years until it was discovered off the shores of Alexandria, Egypt. In 1988, marine archeologists started excavating the ancient city and they believe the whole city was submerged along with statues, columns, artifacts and all. Some of the discoveries included shipwrecks, foundations of the palace, and statues of the goddess Isis and a sphinx. Researchers also found a colossal stone head which they believe to be of Caesarion, the son of Cleopatra and lover Julius Caesar.

So far, archeologists have discovered over 20,000 sunken objects under the sea and we assume that figure will only keep growing.

19 A train graveyard

In 1985, researchers discovered a locomotive graveyard off the coast of New Jersey, United States. Researchers predict it dates back to around 1850, but there is no record of why these trains were dumped into the ocean. There’s no record that they were even built in the first place.

When historians were brought in on the investigation, they believe they could have fallen off a barge accidentally or been thrown off a ship to stop it from sinking. This train graveyard is a spectacular sight and while the trains are rusty, they are generally in good shape considering their age.

18 Sea monsters – they’re no legend

Advanced technology has done a lot of wonderful things for our world. Now we are able to send cameras further down into the ocean to see what’s going on down there…thanks to advanced technology. In fact, most of the discoveries archeologists have made would not have been possible without it. Although we’ve seen our fair share of strange discoveries on here, one of the weirdest has got to be the discovery of sea monsters.

These odd looking sea creatures are for real and live at the very bottom of the ocean. Just look at the blobfish and we’ll see that’s it a pretty bizarre creature living in the ocean.

17 A 2,050-year-old Roman shipwreck

It must be a fascinating job for these marine archaeologists making all these discoveries, some of which date back thousands of years. It can’t be the dullest job in the world anyway, let’s just say that. So we expect they were anything but unhappy to discover another Roman shipwreck off the coast of Antikythera, Greece back in 2015.

After 40 hours underwater, divers discovered interesting artifacts like ancient board games, a bronze armrest, luxury ceramics and a bone flute among other things.

16 Ancient naval battle weapons

In 2013, archaeologists discovered a plethora of artifacts off the coast of Sicily. What they found was the site of the first ancient naval battle, comprising of weapons, armor, helmets and battering rams dating back 2,000 years. That’s some pretty old stuff down there. It’s incredible to think that all these items have remained intact after two millennia.

They are the remains of the battle of the Egadi Islands in which the Romans took on the Carthaginians for over 20 years. Around 50 Carthaginian ships were sunk and the priceless stash of artifacts has sat on the seabed for two millennia.

15 An ancient computer

It’s hard to believe that computers could have existed before Apple or Microsoft. Yet, it seems that could be possible or better yet, is possible. Between 1900 -1901, researchers discovered the Antikythera mechanism, off the Greek island with the same name. It is the earliest form of a computer seen on the planet. The Antikythera is an analog computer that was built to serve several purposes. One of those purposes includes predicting the astronomical eclipses and positions on the calendar.

If anyone’s interested in seeing it for themselves, the computer is now on display at the National Archaeological Museum of Athens.

14 An old Roman medicinal pill in a shipping vessel

The last thing researchers probably expected to find in a shipping vessel was an old Roman medicinal pill and yet, that was exactly what they found. See, you never know what you’re going to find when you’re at the bottom of the ocean. The pill was discovered in the Relitto del Pozzino, a submerged shipping vessel that dates back 2,000 years. In 2013, Italian scientists studied the medicinal pills discovered off the coast of Tuscany, to gain a deeper understanding of what the ancient Romans used as medicine.

They contained zinc compounds, starch, iron oxide, beeswax, and other plant-based materials. The scientists believe the tablets were used as an eye medicine.

13 A Bronze Age sewn boat

In March 2014, marine researcher Giulia Boetto at the Center National de la Recherché Scientifique (CNRS) in Croatia revealed the discovery of a Bronze Age sewn boat in Zambratija Cove, Croatia. The boat wreck was dated to 1,200 BC. In other words, it was quite a remarkable discovery for the marine researcher.

This wooden boat is sewn together by roots, ropes, or maybe willow branches. Either way, it is an incredible sight that gives us a glimpse into how boats were made thousands of years ago. Measuring seven meters in length and 2.5 meters in height, the remains of this boat are incredible considering it’s at least 3,200 years old.

12 Elongated skulls in a submerged cavern

Researchers find some unique artifacts deep down in the ocean, but little could be as unique as human skulls. We can’t even imagine how unsettling that must be to discover such things under water. Yet that’s exactly what researchers found in a flooded sinkhole in Mexico back in 2014 – elongated skulls and human bones.

Known as Sac Uayum, the underwater cavern is a natural pit from a limestone bedrock collapse. The team of researchers discovered over a dozen human remains down there, though it has not yet been discovered the cause of death of these skulls' owners. What we do know is that this stuff is creepy!

11 An exploded star

A long, long time ago, before any of us were born, a star exploded and pieces of it landed in the Pacific Ocean. It was no ordinary star that exploded, it was a Type II supernova, the kind that ejects iron-60 during an explosion.

German researchers discovered the phenomena while drilling in the Pacific. The star fragments were actually discovered in the remains of a magnetic bacterium, which feasted on the stellar iron. It must have happened around 2.7 million years ago because iron-60 is way too young for Earth. Scientists predict it occurred from a supernova explosion.

10 Stone Age items

It’s not often we find Stone Age items in the ocean. So we can imagine the surprise and accomplishment Swedish divers felt when they found artifacts dating back 11,000 years in the Baltic Sea. The researchers believe they are discarded remnants by Swedes in the Stone Age.

In spite of the sediment and the lack of oxygen, these remnants have preserved well. That’s pretty hard to believe considering they are buried 16 meters below the surface. Researchers found animal horns, flint tools, uncovered wood and ropes.

9 10,000 year old underwater ruins

Sometimes, it’s hard to believe how well these ancient items are preserved when researchers find them all these years later. And in the case of the Yonaguni, Japan, we’re not just talking 5 or 10 years later, we’re talking 10,000 years later.

Some experts say it was man-made, while others argue it was created by natural phenomena. These ruins are some of the most interesting findings researchers have discovered underwater. The fact that they’re at least 10,000 years old is even more fascinating.

8 Lord Krishna’s Lost City

For a long time, people considered Lord Krishna’s city of Dwarka a myth. That was until a group of Indian scientists discovered the lost city submerged off the northwestern coast of India. That’s when they knew for sure that it was real because they’d seen it with their own eyes.

Findings suggest that Dwarka used to be a busy port center. It is lucky that researchers refused to believe it was a myth because Lord Krishna’s Lost City is simply amazing.

7 Remains of Gondwana

According to a National Geographic article published in 2011, huge pieces of Gondwana, an ancient continent comprising of Australia, India and Antarctica were discovered submerged in the ocean. They were actually formed when the landmasses separated into their current locations and sizes.

In order to explore it more, deep-sea exploration was needed and so that was exactly what happened. Scientists discovered many unique features during their search: for example, the presence of gneiss, granite and sandstone. In spite of everything they’ve found, there is still much that remains a mystery about Gondwana and its remains. That calls for more research.

6 The temples of Mahabalipuram

Another interesting discovery comes forth: the seven pagodas of Mahabalipuram. It lies off the coast of Tamil Nadu, in the Indian subcontinent. Indian mythology says the seven temples did exist here. Unfortunately, only one temple was discovered during an expedition of the ocean location. Steps, broken pillars, foundations and scattered stone were a few of the findings from the investigation. It is definitely one of the biggest and most significant discoveries in the region.

We don’t doubt that researchers are desperate to find the other six…wherever they are.

5 17th-century Port Royal

Two-thirds of Jamaica’s 17th century Port Royal sank into the Caribbean due to an earthquake and tsunami on June 7, 1692 precisely at 11:43. How can we give such an exact time? That’s owing to the finding of a pocket watch with its hands frozen at the time of disaster. It’s freaky, but exciting all the same.

Researchers must have been thrilled to find such an incredible discovery that provided them with such accurate detail about this specific event. It is actually one of the few disaster sites where the cultural material is found practically undisturbed. This is most likely due to the oxygen-depleted environment.

4 An entire town is resting under the ocean

As fascinating as it is to hear about and see, it’s also somewhat frightening that the City of Pavlopetri in Greece is resting underwater. We know it’s common to discover ruins under the ocean, but entire towns?

According to scientists, the City of Pavlopetri is around 5000 years old. The streets, buildings, tombs and courtyards of this city are all resting underwater. At least 15 buildings have submerged in four meters of water. Pavlopetri used to be a thriving harbor town where its locals conducted long distance trade through the Mediterranean. This discovery has offered major insights into the society of Mycenaean.

3 Emerald treasure

It’s like something out of a fairytale. Well, it’s not every day we hear about treasure hunters finding treasure, is it? Jay Miscovich may have been an amateur treasure hunter but he but he didn’t do too bad when he discovered 10,000 emeralds off the coast of Key West in Florida back in 2010.

The emeralds were worth at least half a billion dollars. Miscovich, thinking he’d won the jackpot, didn’t waste time in spending his wealth. It wasn’t until the Federal Government of the United States granted him temporary ownership of the emerald jewels, making it illegal for him to sell them, that his wealth turned into major debt. Miscovich actually said goodbye to the world three years later.

2 Jurassic microbes are still hanging on

An abundance of microbes lives beneath ocean sediments. In fact, at least 90 percent of earth’s unicellular organisms are found there. But can these microbes survive if they eat nothing for, let’s say, 86 million years?

In 2012, microbes dating back 86 million years were found in deep sea water in the Pacific Ocean. They were alive, but barely hanging on. Even researchers were surprised that after millions of years of starvation and little oxygen to sustain metabolism, these little guys were still chugging along, even if only just. That makes them the oldest organisms on the planet. Now that is quite a discovery!

1 RMS Republic

In 1981, researchers located the RMS Republic, an ocean-liner built in 1903 and lost at sea in 1909. It is believed that the ship went down with a whole lot of treasure that could be worth billions of dollars.

Without a doubt, there are a number of rumors circulating around this ship. One of them is that the RMS was carrying USA gold coins worth a minimum worth of $250,000. Another rumor is that the ship was carrying $3,000,000 in coins as a loan to Russia. Unfortunately, the treasure itself was never found. But we have a feeling researchers and treasure hunters especially aren’t going to give up too soon.

References: ancientpages, ancient-origins, history.co.uk, slavorum.org, sott.net, dailymail, news.nationalgeographic