Below the surface of our planet’s oceans, seas, and lakes, underwater archaeologists hunt for clues about cultures that haven’t seen the light of day in years — and in many cases, in centuries or even millennia. While there’s something undoubtedly eerie about exploring shipwrecks and sunken cities, these long-lost sites are absolutely fascinating. Archaeologists do have to take special care to avoid getting hurt or destroying the underwater sites’ artifacts, but the tradeoff makes the effort worthwhile: their research often turns up incomprehensibly invaluable insights.

In that light, we’ve compiled the stories of four underwater sites where archaeologists are currently dredging up incredible secrets. Let’s dive in!

Port Royal, Jamaica

In the late 17th century, Port Royal was a wealthy, bustling English port. It had a reputation for debauchery, and its streets crawled with pirates, privateers, and prostitutes. Minor earthquakes occasionally shook the area, but no one was overly concerned about the shallow water table or the loose soil that Port Royal was built upon.

But shortly before noon on June 7, 1692, a series of three earthquakes wreaked havoc on the town (an event that many New World clergymen referred to as an act of God). Scientists estimate that the strongest shock registered a magnitude of 7.5 on the Richter scale, a disaster that instantly liquefied the soil. The sea quickly swallowed 33 acres of buildings and streets, with part of the city disappearing to a depth of 10 feet (three meters) and other areas sinking all the way to 35 feet (11 meters). The force was so strong that, in the local cemetery, corpses spilled out of their graves and joined the drowning townspeople in the swirling, chaotic water.

Minutes after the third earthquake, a tsunami hit the city and launched the HMS Swan across the harbor, dropping it on the rooftops of a few still-standing buildings. In total, about 2,000 people died that day, with thousands more succumbing to starvation and disease in the following weeks. Most of the city was doomed to remain underwater.

Today, the archaeological site has survived for more than three centuries, preserving a perfect snapshot of 17th-century life in Port Royal — a rare opportunity that has allowed research teams to spend over 60 years studying the submerged streets. So far, the most significant artifact recovered has been a pocket watch that stopped at 11:43 a.m., confirming the exact moment that disaster struck.

Although the day’s events dragged most of Port Royal into the Caribbean, part of the city survived. Since then, the town has been besieged by hurricanes, fires, and more earthquakes, but tourists are still welcome to drop by and pay their respects. If you choose to visit, be sure to check out Fort Charles and the Old Gaol House, two structures that endured the tests of the 1692 disaster.

Thunder Bay, Michigan (USA)

The five Great Lakes act as the watery grave of a staggering 6,000 ships. And in Thunder Bay, on the northwestern shores of Lake Huron, almost 80 shipwrecks are protected within a national marine sanctuary. The cold freshwater keeps the wrecks fairly intact, allowing archaeologists to locate and identify them with relative ease. These underwater ships reflect more than two centuries of North American maritime history, and they include everything from wooden schooners to steel-hulled steamers.

From the Maid of the Mist (a two-masted ship lying in only seven feet of water) to the Heart Failure (a broken-up barge that sank in the early 20th century), each shipwreck tells a story, and while many are tragic, a few are somewhat amusing. For example, the Grecian sank in shallow water in 1906. Not willing to lose it, crews raised the freighter and began towing it to Detroit for repairs. But en route, the Grecian filled with water and sank again; fortunately, all crew members escaped in lifeboats.

Two of the most famous ships housed in the sanctuary sank in 1854. At that time, the region’s shipowners insisted on quick trips across the Great Lakes, not caring whether or not shipping lanes intersected. This explains why, after a thick fog had settled over Lake Huron on an October night, the John J. Audubon and the Defiance collided. Both were wooden schooners, one carrying a shipment of iron and the other a large amount of corn, and neither ship made it through the night. They sank just a few miles apart from each other, the Defiance settling on the lake bottom in an upright position. Today, divers often remark how strange it is to see an apparently seaworthy ship 185 feet (56 meters) below the surface.

What makes the Thunder Bay shipwrecks truly special is that archaeologists aren’t the only ones who get to explore them — in many cases, divers and sightseers can see them up close, making the wrecks much more impactful. That said, divers should always avoid sites that lie beyond their certification level or comfort zone, and non-divers should choose to explore the wrecks in a glass-bottomed boat cruise.

Atlit-yam, Israel

Just south of modern-day Haifa, an ancient Neolithic village lies submerged in the Mediterranean Sea. The village, known as Atlit-yam, dates to somewhere between 6900 and 6300 B.C., and at its shallowest point, it sits 26 feet (eight meters) below the surface.

A few finds make Atlit-yam truly remarkable. While the site’s structures include homes, walls, and even wells, many people are most interested in the stone semicircle that once stood next to a freshwater spring. Made up of seven megaliths (massive stone markers), this formation was used in rituals that probably had something to do with the nearby water source.

Archaeologists have also found the remains of 65 individuals, including a mother-child duo suffering from tuberculosis (the world’s earliest documented cases of the disease) and several adult men with an inner ear condition. They developed their ear conditions by taking frequent swims in cold water — so, given the vast amount of fish remains in the village, researchers have concluded that the locals must have fished by diving offshore.

The site’s biggest mystery (and biggest source of controversy), however, is how it ended up underwater. Some scholars believe that a tsunami destroyed Atlit-yam, citing a contemporary eruption of Sicily’s Mount Etna. They also point to the site’s large stores of food and say that the residents had no idea they were about to lose their village to the Mediterranean. However, other researchers have hypothesized that Atlit-yam was a victim of rising sea levels that contaminated the freshwater and eventually buried the city.

Whatever the explanation, archaeologists have been exploring the site since 1984, and they still have a lot to learn.

Baia, Italy

Not far from central Naples, the resort town of Baia used to be one of the most popular getaways in the Roman Empire, playing host to people like Nero, Caesar, and Cicero. Like other visitors, they spent much of their time relaxing in spas built over the town’s natural hot springs. Throughout Baia, the villas and streets were full of Roman hallmarks, like elaborate mosaics, classical statues, decorative fish ponds, and central courtyards.

But the grandeur wasn’t destined to last forever. Just like the Roman Empire itself, Baia gradually declined, growing weaker in a series of sackings by enemy groups. It did outlive the empire, but by 1500, all of the residents had deserted their resort town.

The following centuries didn’t treat the abandoned town much better. The viceroy of Naples did build a castle in the area to protect the bay, but because of the volcanic activity that had made Baia’s spas famous in the first place, many Roman ruins sank below the waterline. Their disappearance drove the town out of the public’s mind, and eventually, people forgot that it had ever existed.

Construction crews discovered the ruins in the 1920s, and a pilot captured aerial shots of Baia’s hidden treasures in the 1940s, but for decades, archaeologists had little to do with the site. Finally, scholars began surveying Baia and recovering finds, and today, it’s an archaeological park that’s located partly aboveground and partly underwater. Whether visitors choose to tour the museum (where they’ll find many original statues) or dive to its underwater sites (where mosaics, columns, and other structures await), Baia makes for an exciting field trip.

Unlike many archaeological sites, Baia’s history was relatively peaceful, and the town never experienced any major catastrophes. What’s more, its forgotten ruins are easily accessible to scuba divers of all skill levels — so, the next time you venture to Italy, you might want to add Baia to your itinerary!

Would you ever consider diving to underwater ruins? Let us know why or why not in the comments below.

Header image by National Marine Sanctuaries