Photos: Turkish tunnel links Europe, Asia

Fireworks explode above the Bosphorus Strait in Istanbul on Tuesday, October 29, during the anniversary of the declaration of the Turkish Republic. On Tuesday, Turkey formally opened the world's first sea tunnel connecting two continents. The Marmaray <a href='http://www.cnn.com/2013/10/29/business/marmaray-tunnel-turkey-john-defterios/'>links Istanbul's European and Asian sides</a> under the Bosphorus.

Fireworks explode above the Bosphorus Strait in Istanbul on Tuesday, October 29, during the anniversary of the declaration of the Turkish Republic. On Tuesday, Turkey formally opened the world's first sea tunnel connecting two continents. The Marmaray links Istanbul's European and Asian sides under the Bosphorus.