The mountains of Transylvania may not be haunted by vampires, but they are full of gold that attracts what some view as predatory attention, in a battle that refuses to die. The bitter fight concerns a foreign company's proposal to build Europe’s largest open-pit gold mine at a historic site called Roșia Montană.

In the picturesque Apuseni Mountains, peppered with castles and forests, people have dug gold and silver from the Earth for more than 2,000 years. Roșia Montană contains the world’s largest and most important intact Roman mining tunnels—with rarities like writing tablets and water wheels that once controlled water flow in the galleries, says Andrew Wilson, an Oxford professor of archaeology who co-authored a study of