The incredible £858 million tunnel that connects two continents is just three miles long

Turkey straddles both Europe and Asia, offering a fascinating mix of cultures and identities.

Geographically, the country is located in southeastern Europe and southwestern Asia, with a total surface area of 301,382 square miles.

European Turkey is relatively small compared to the Asian part, the Anatolian Plateau, which is a large peninsula.

The country's most famous city, Istanbul, connects Europe and Asia and is split by the Golden Horn and the Bosphorus Strait which links the Sea of Marmara to the Black Sea.

The connection between the two continents has been facilitated by the construction of a three-mile-long tunnel, which opened to much fanfare on December 22, 2016.

Its construction was part of a wider infrastructure scheme known as the Eurasia Tunnel Project, which involved building a 9-mile road linking Turkey's two continents.

The three-mile-long twin-deck tunnel was built underneath the seabed of the Bosphorus, also known as the Istanbul Strait, and has a capacity of 120,000 vehicles in both directions.

The project also involved the improvement and widening of the roads leading to the tunnel.

Its construction has cut the time of travel between Kazlicesme in Turkey's European part to Goztepe in Asia from 100 minutes to just 15.

The whole project was divided into three segments: European Side Approach (3 miles), Asian Side Approach (2.4 miles) and Istanbul Side Approach (3 miles).

Two miles of the tunnel passes underneath the seabed, which was designed to withstand earthquakes of a magnitude up to 7.5 on the Richter scale.

Its maximum depth below the seabed is 61m, while the lowest tunnel level is 106.4m. The project cost USD 1.1 billion (£858m).

The tunnel has extensive safety features, including equipment aimed at detecting fires quickly.

There are 5,500 fire detectors in the tunnel. Automated detectors, sounders and manual call points ensure that any fires can be detected almost as soon as they break out.

More than 100 emergency phones on each level have been installed as an additional safety feature for drivers.

Not only has the Eurasia Tunnel eased traffic congestion in Istanbul, it has also contributed to the growth of Istanbul’s air transport by providing the most practical link between the city’s two airports, namely Ataturk and Sabiha Gokcen Airport.

By decreasing distance, it indirectly contributes to reductions in fuel consumption, noise pollution and CO₂ emissions.