Welcome to the Inland Sea in Dwejra, Gozo - a huge round hole in the ground with a lagoon inside it.
Why you should visit
This site is just one of several amazing wonders in Dwejra, Gozo. From a geomorphological point of view, the Inland Sea may just be the most interesting feature in the area; most certainly so after the more famous Azure Window collapsed in March 2017.
The sinkholes of Dwejra, Gozo
Apart from the Inland Sea, Dwejra hosts three other sinkholes, namely Dwejra Bay, Berwin and the smaller Blue Hole. The causes for sinkholes vary considerably. In Malta, rain water seeping through the ground may dissolve limestone, evaporite (natural salts) or gypsum (as in the case of Dwejra) below ground with its slightly acidic pH. As a cave is formed, the weight of the unsupported ‘ceiling’ eventually gives way, leaving a deep, usually rounded depression in the ground. The depression containing the Inland Sea measures between 300m and 400m in diameter.
The Inland Sea
The Inland Sea, Il-Qawra in Maltese, was born when open sea came into the sinkhole through an 80m tunnel, L-Ghar tad-Dwejra in Maltese, which was naturally carved through the rock, thus forming a lagoon.
The Inland Sea Tunnel
The Inland Sea Tunnel was formed by a phenomenon similar to that which forms coastal arches such as the collapsed Azure Window or the Mielah Window. The process of formation of natural arches on the coast finds seawater seeping through a crack in the rock, with the power of the waves enlarging the crack. With time, rock weakens and falls, making the gap bigger and wider. Today, that crack is a tunnel that connects the open sea to the deep sinkhole depression, filling it up with sea water and creating the Inland Sea.
What to do at the Inland Sea
The Inland Sea Tunnel, along with the Blue Hole and the ruins of the Azure Window, are a favourite diving destination in the Mediterranean. Scuba divers enter the tunnel at the Inland Sea and exit in open sea, or vice versa.
This exciting dive is known for its ambiance such as the play of light on walls covered with coral and sponges. Deeper inside the 80m tunnel, divers require a dive light. Since the tunnel is also used by boats, a safety agreement requires divers to keep to the left wall on the way out, and use the same side on the way in. Surfacing should be avoided due to the danger from boats.
If diving is too adventurous for you, hop onto one of those boats and get a tour of the Inland Sea tunnel, the area of the collapsed Azure Window, and the Fungus Rock, which is also located at the site of a huge sinkhole.
Do take the time to explore the rest of the area of Dwejra - it is indeed a formidable place!