The numbers still astonish. Designed by the Italian architect Antonio Gherardi, who had also built the customs house in nearby Bahía Blanca, the hotel could sleep 350 guests and rivaled the finest in the world. It had a solarium and a night club, a ballroom seating 150 where films were screened, two beauty salons, a concert hall, a well-stocked library, a tower with panoramic mountain views, a chapel, a polo field, a football pitch, three tennis courts, a riding stable, a swimming pool, even its own hospital and pharmacy. The bricks came from the works of Ernesto Tornquist, the entrepreneur whose vision animated the whole enterprise. Around the building, the French-born landscape architect Carlos Thays laid out a 126-hectare park planted with European trees, a transplanted slice of the Old World dropped into the Argentine grass. Construction had begun in 1904; it took seven years to complete.

The hotel opened to the public on 1 December 1911, and for a few years it played its part. In 1916 it hosted a glittering celebration for the centennial of Argentine independence, drawing the Crown Princess of Spain, the future King Edward VIII, and the President of Brazil. A daily train connected it to Constitución station in Buenos Aires. But the timing was cruel. Losses mounted from 1913 as global depression and the outbreak of war in Europe drained the flow of wealthy travelers. Then came the decisive blow: on 3 November 1917, President Hipólito Yrigoyen banned gambling in Argentina, and a casino-hotel without a casino had lost its heart. In 1920 the mostly English owners gave up and closed the doors. The company that ran it went into liquidation, and the great rooms fell silent.

For a strange interlude, the empty hotel filled with men in a foreign navy. In December 1939, the German pocket battleship Admiral Graf Spee, cornered after the Battle of the River Plate, was scuttled by her captain Hans Langsdorff in the harbor of Montevideo. More than a thousand of her sailors were brought to Argentina and interned. In December 1943, around 350 of them were carried by special train and army truck to the Club Hotel, where the government held them and set them to refurbishing the decaying building. For a brief season the place came back to life, its corridors echoing again with voices, this time German ones, far from home and uncertain when they would return. In February 1946 the crew was finally repatriated to Germany as prisoners of war. Some would later come back to Argentina, marry, and stay.

When the sailors left, the hotel had no one. It had already been looted once in the 1920s, when a provincial plan to turn it into a holiday center for teachers and students came to nothing and the fine wines and furniture simply walked away. Now decay set in for good. Demolition began in 1978, and on 8 July 1983 a fire consumed most of what remained. What stands today is a haunting ruin: bare brick walls and empty window frames open to the sky, the European trees of Thays's park grown wild around them. People still climb the hills to walk through the marvel of the century, now a monument to ambition outrunning its moment. A grand idea, magnificently built and quickly abandoned, slowly returning to the wilderness it tried to tame.