Holding up his mobile phone screen in front of a ferry pier near the Lei Yue Mun channel in Hong Kong, Stephen Law Kwok Hing, managing director of Gateway Cuisine, a well-known seafood restaurant, was feeling nostalgic.

Looking at scenes of the old stone quarry and time-honored brands brought back memories of the then fishing village that existed here, and he says he thought of his late father. "I feel reunited with him in another way."

Law was viewing this scene of the past through a special app, called "City in Time", a cultural and creative tourism project launched in 2021 by the Tourism Commission of the Hong Kong Special Administrative Region government.

The project is the world's first tourism project to fully apply augmented reality in an urban environment, to enrich the experience of Hong Kong through the combination of art and technology.

On Pedder Street, a major thoroughfare at the heart of Hong Kong's Central District, people can scan a QR code for the "AR clock "and instantly get a 360-degree panoramic image contrasting old Hong Kong with today's surroundings, pieced together from photographs or paintings by local artists based on historical data.

Everything is brought to life in just a few seconds, impressing her with what is changed and unchanged. People are able to imagine traveling through time to the last century, as antique "Ding Ding "trams passed by along retro-looking streets. But with a swipe, they can magically return to modern-day Hong Kong.

Developed and produced by the School of Creative Media of the City University of Hong Kong on behalf of the Tourism Commission, the project was launched at 28 locations across Hong Kong. With a mobile phone with the app, people can travel through time to a kaleidoscopic Hong Kong of the past.

Restoring memories is by no means an easy job. Many streets no longer exist, so the team collected pictures, videos, sounds and other materials, and consulted historians to help create virtual 3D models, and even invited young artists to draw different angles of the buildings and character illustrations, according to Jeffrey Shaw, artistic director of the "City in Time "project, and chair professor at the Academy of Visual Art of Hong Kong Baptist University.

There was once a busy seafood business in Lei Yue Mun, says Law, who has been living in the area for nearly 70 years. As a witness to the changes, he says he is quite impressed by the "AR clock", which re-created animated scenes of the area's bustling seafood business, as well as of waiters flagging down and serving customers, "Technology can have that human touch, surprisingly."

In addition to visual arts, the team also asked a professional sound editing company to create authentic sound effects and retell old stories.

"City in Time" has emerged from a budding need for immersive tourism that blends culture and creative technology, and is boosting tourism by enriching the travel experience.

Tourists can now have a clearer picture of how the fishing village of Lei Yue Mun evolved into a seafood paradise of food, cultural and artistic activities and historical buildings. By focusing on the daily life of fishermen, the app creates an attractive, lively vibe.

But that is not all it offers. As a result of upgrades, the app now includes filters and permits users to shoot short films with its selfie function, as well as 3D animations.

Huang Wei, a Hong Kong film fan who was recently in the city on her summer vacation, says that she could not wait to visit the site of classic Hong Kong films such as C'est la vie, mon cheri and Internal Affairs, and was on her way to Temple Street in Kowloon's Yau Ma Tei district to relive classic Hong Kong film clips and recapture moments from the films.

There is just so much more about Hong Kong to bring to life, says Richard Allen, chair professor of the School of Creative Media at the City University of Hong Kong and the team's project director, adding that they are ready to expand the app to cover every corner of the city, including Tai Hang and Kowloon City.