"Most of the bookings were from people born in the 1990s and early this century who use shortvideo platforms frequently and tend to spend more on travel," he said.

With their great sightseeing opportunities and cultural experiences, Xi'an and Chongqing have been hot domestic destinations, Wu said. This has provided a good foundation for the cities to go viral in the era of short-form videos.

"Among the large number of tour groups that arrive every year, some, particularly those with younger people, shoot videos of unique scenery or experiences during their trips and post them on social media platforms, attracting increased attention and luring more tourists to the destinations," he added.

As a result, new tourists arrive and shoot their own videos, and the process is repeated, forming positive feedback, Wu said.

Jia, at Ctrip, said convenient transportation and reasonable prices have also contributed to the popularity of Xi'an and Chongqing.

"Easy access to the two cities - whether by air or rail - and relatively low costs for tourists make them destinations for many people to 'sign in'," she said.

In a written reply to China Daily, the Xi'an bureau of culture and tourism said that as more high-speed railways between the city and those in neighboring provinces came into service in the past two years, Xi'an had attracted visitors from places about three hours away by rail, such as those in Gansu province and Sichuan.

A survey by the China Tourism Academy last year found that with each tourist spending 3,133 yuan on average, Chongqing was the cheapest tourism destination in Southwest China. The figure for the Tibet autonomous region was 9,222 yuan, for Yunnan 5,109 yuan and for Sichuan 4,440 yuan.

The survey also found 35 percent of tourists to Chongqing spent no more than 2,000 yuan during their stay, 57 percent spent 2,000 to 5,000 yuan, and only 8 percent spent more than 5,000 yuan.