Ryan Gosling and Eva Mendes in Paris
Pacific Coast News
and Eva Mendes
are checking out the dark side of the City of Light.
The affectionate couple
, who've been dating since September
, spent Saturday afternoon visiting the legendary cemetery Pere-Lachaise in Paris, where she's has been filming Holly Motors
Gosling, 31, and Mendes, 37, enjoyed red wine and Argentine fare Friday night, before visiting the resting place of Jim Morrison, Édith Piaf and Oscar Wilde, which is known as the City of the Dead.
"They were holding hands and there was a lot of tenderness between them," an observer tells PEOPLE.
From Pere-Lachaise, they continued their grisly tour at the historic Catacombs of Paris, where visitors can go below ground to see the ancient stone quarries that make up the ossuary, which houses the skeletal remains of approximately six million Parisians.
Creepy ... but trés romantique