A foreign doctor operates in Guiyang during the war. Photo Provided to China Daily

He talked about how, even though they were faced with the horrors of war every day, the foreigners would still throw parties and sing and dance with the locals late into the night.

But the story that stuck with Yang most was that of a young British female doctor, Guy Courtney.

The site where the hospital once stood is now a popular recreation area - Senlin Forest Park. Walking down its shaded paths, Yang passed wild monkeys cavorting in cherry blossom trees and men and women of Zuo's age doing their morning calisthenics.

At the center of the grounds she paused in front of a memorial built to honor the wartime service of the doctors, Chinese and foreign, before she moved on to a small shrine of remembrance bearing an inscription in English that reads: "Dr Courtney died at her post in 1942 while working to prevent and cure the disease caused by the germ warfare waged by the Japanese."

Yang said the young doctor was the victim of a germ bomb dropped by Japanese aircraft.

"She was trying to find a cure," Yang said.

As the morning grew older, a crowd gathered at the memorial. Speeches were made; wreaths were laid; old patriotic songs rang out; Red Cross uniforms abounded.

The locals had come, as they frequently do, to honor the memory of the doctors.

Yao Renli, 89, was among them.

"I didn't know the doctors," he said. "I just come here to pay my respects."

Du Yang, the park's deputy director, said many thousands of patients were admitted to the hospital every year between 1939 and 1945.

He gestured down the mountainside toward the modern city silhouetted against the sky.

"The wounded were brought up here on stretchers or by horse," he said.