New 'underground cathedral' opens ahead of Paris Olympics

The giant new structure, burrowed 30 metres deep (100-feet) in the ground next to a train station, is a key part of efforts to clean up the river Seine which is set to host swimming events during the Paris Olympics in July and August. "I like to say that we're building two cathedrals," deputy Paris mayor Antoine Guillou told reporters during a visit to the site in mid-March. "There's the one above ground that everyone knows, Notre-Dame. And then there's the one underground." Notre-Dame will not be ready in time for the Paris Games...