Much of Kulangsu's beautiful landscape and many of its historical buildings were destroyed or damaged, and even ancient trees were uprooted in the typhoon's path of destruction. Some 3,000 trees were badly damaged and in need of timely care. In addition, 25 walls collapsed, and more than 25 roads were blocked by fallen trees and debris. A year later, there are still visible signs of the destruction.

What happened next was an incredible show of solidarity and resilience. "People from over 12 countries were involved in the cleanup exercise, making the effort representative of Kulangsu's international and multicultural history," said Zhang Xiaojuan, who runs a small hotel and volunteered in the wake of the typhoon.

In the control room at the Kulangsu World Cultural Heritage Monitoring and Management Center, Cai shows footage of that dreary night and its aftermath. "It also affected the people," he said. "Even though no one was hurt, this event will be imprinted on our minds forever."

  Cai Songrong in the control room at the Kulangsu Monitoring and Management Center (MA LI) 

Diversifying the activities 

A disaster of such scale did not dash Kulangsu's spirits though. A UNESCO inspection team made a satisfactory visit to the island a month later. The rest is history.

With the new status comes new responsibilities and challenges. Being a World Heritage Site will undoubtedly increase Kulangsu's domestic and international profile, raising the question of reconciling tourism and preservation.

According to Cai, the management and preservation of Kulangsu's cultural and environmental heritage is a complex equation of controlling the number of tourists and reducing pollution and degradation. Kulangsu has taken drastic measures to control the daily influx of visitors during peak season.

"One day in 2012, we hit the 120,000 mark. It was an all-time record," he said. "The concentration was so high that the streets were chock-a-block with people. We had reached saturation point. It had to stop."

In 2014, authorities imposed a ceiling on the total number of visitors per day at 50,000 and implemented a new ticketing system, resulting in significant reduction of garbage, waste water and sewage, and noise pollution.

"We have set up a live monitoring system that enables us to know how many visitors are on the island at any time," explained Cai, in front of a giant screen in the control room. "We allow 30,000 visitors on the island at any given time during the day, and we have a warning system in case of overcrowding."

"Noise pollution is limited to 100 decibels. We got rid of street hawkers and have specific regulations regarding loud music," he said. Furthermore, outside barbecues are strictly forbidden to reduce air pollution. "The level of fine particles (PM2.5) on average remains as low as 20 and the AQI (Air Quality Index) varies between 20 and 50 all year round."

Another significant task Kulangsu faces is drawing more international visitors and mainland individual tourists who are more educated and have higher spending power, not just tour groups, day-trippers and backpackers. The island has already gone upscale in recent years, but there's still plenty of room for improvement.

"The next step is to look further ahead. We are planning a museum dedicated to the island," said Cai. "We have also planned international conferences, sporting and cultural events and exhibitions."

Kulangsu is now entering a new era, more focused on sustainable development and quality and more aware of future challenges, but also better equipped to address them.