Turkey has opened an underwater railway tunnel in Istanbul linking Europe and Asia.
Tens of thousands of people, as well as Turkish Prime Minister Recep Tayyip Erdogan and his Japanese counterpart Shinzo Abe, attended the ceremony.
Japan invested $1 billion of the $4 billion cost of the project.
Officials hope the tunnel will carry up to 1.5 million passengers a day and that it will ease some of Istanbul's chronic traffic, particularly over the two bridges that connect the two sides of the city.
Work began in 2004, but archaeological excavations delayed construction. The tunnel was inaugurated on the 90th anniversary of the Republic of Turkey.