ISTANBUL -- As a country, Turkey is often described as a bridge between Europe and Asia. On Tuesday, for the first time, the two continents will be officially connected by a multi-billion dollar underwater railway tunnel.
Turkey's Prime Minister Recep Tayyip Erdogan and President Abdullah Gul, Japanese Prime Minister Shinzo Abe, Romanian Prime Minister Victor Ponta and numerous transport and trade ministers are gathering to inaugurate the giant rail system, on the country's republic day.
The Marmaray link, named by combining the Sea of Marmara with "ray," meaning rail in Turkish, is a part of $4.5 billion, 76-kilometer mega-project launched by the government in 2004.
Its scale, along with designs for a third airport, a parallel canal for the Bosphorus river and a third suspension bridge, are seen as overly ambitious plans by Erdogan to build his legacy and hark back to days of the Ottoman Empire.
The bold project brings the dreams of Sultan Abdul Medjid, first outlined more than a century ago, to reality as the Turkish Republic celebrates its 90th anniversary.
It is finally being completed by Erdogan after he faced intense protests for the redevelopment plans of a central Istanbul park with Ottoman-era military barracks and a mosque. The 13.6 kilometer (8.5 miles) tunnel -- the deepest of its kind -- passes under the Bosphorus Strait, one of the busiest shipping arteries in the world.
For more on this CNN story, click here.