Most people know about Pompeii, the Roman city near Naples, but few know about Baia which was about three times the size of Pompeii. While Pompeii was covered in volcanic ash, Baia was abandoned in the 8th century and then submerged underwater. Today it can best be explored by snorkelers and divers.
Just a few kilometers north of Naples near Pozzuoli (where Sophia Loren is from), visitors can visit the Baia Underwater Park. The city was once a lavish seaside resort for rich Romans and even the emperor Caligula. Historians today compare it to Las Vegas or Beverly Hills. On clear summer days, visitors can travel by glass-bottomed boat to see the ruins. There are also snorkeling excursions, but the best experiences will be had with SCUBA equipment. With the guidance of a local instructor, you'll be able to swim between marble sculptures and touch the mosaic floors.
Excursions are led by Centro Sub Campi Flegrei.
The city of Caesarea in Israel has been the center of many excavations over the past 30 years. In 2006, the so-called "Herod's Harbor" was opened as an underwater museum focused on one of the largest ports of the Roman Empire, inaugurated in 10 BCE.
Visitors float from exhibition to exhibition to see a ruined lighthouse, original foundations, anchors and pedestals. There are 36 different sign-posted sites along four marked trails of the sunken harbor. Visitors are also given a water-proof map. One trail is accessible to snorkelers while the others are all designed for beginning divers.
The reason it's called Herod's Harbor is that Caesarea (Roman) was built by Herod on the ruins of a Phoenician town called Straton’s Tower. Josephus Flavius, a Romano-Jewish scholar describes the building of the port in "The Jewish Wars."
This underwater contemporary art museum has over 500 permanent monumental sculptures in the waters surrounding Cancun, Isla Mujeres, and Punta Nizuc.
The goal of the museum is to demonstrate the interaction between art and science as well as form a reef structure for marine life to colonize. All the artworks are made from specialized materials that will promote coral life and are tethered to the seabed.
Visitors may see the art via glass-bottomed boat tours, snorkeling and diving routes. An important part of MUSA is to draw some of the 750,000 divers annually who come to the Yucatan peninsula away from the coral reefs.
Just opened in 2016, the Museo Atlántico Lanzarote was inspired by MUSA in Mexico and is the first underwater contemporary art museum in Europe. The installations strive to bring attention to environmental and climate change issues as well as create a new marine habitat for the Canary Islands. Dive instructors lead detailed tours of the nearly 300 sculptures.
Divers can explore a trail of historic shipwrecks in the Florida Keys National Marine Sanctuary. Some sites are very shallow while others are much deeper so there is a variety of experiences.
The oldest shipwreck is the San Pedro which left Havana Cuba bound for Spain in 1733. It was carrying Mexican silver coins and crates of Chinese porcelain. It got caught in a hurricane and without enough time to return to the port, the ship sunk. It was discovered in the 1960s by treasure hunters who helped recover the ballast and cannons as well as remnants of the cargo.
The youngest is the Thunderbolt built during World War II. The vessel was never officially commissioned and was later used for research on the electrical energy in lightning strikes. It was donated to the Florida Keys Artificial Reef Association and intentionally sunk in 1986.