As a visitor who had just finished a tour of the Hong Kong-Zhuhai-Macao Bridge — the world's longest cross-sea bridge — on Friday, Yu Mei said she was impressed by both the beautiful bay scenery and the construction achievements of the bridge.

"As a former engineer, I was so impressed by the magnificence of this national super engineering project after gaining insights into its construction," said Yu, a resident of Zhuhai, Guangdong province, who admired the project on the first day of its trial tourism operation.

During the tour, Yu and other visitors completed a 140-minute escorted shuttle bus ride starting from the Zhuhai end of the bridge to the western artificial island, also known as Blue Dolphin Island.

Yu was one of the first 1,200 tourists to visit the bridge, she said, adding that she paid 188 yuan ($26.4) for her ticket.

According to the official WeChat account of the bridge tour, prior booking is required and can be done via WeChat, with ticket prices varying from 128 yuan to 298 yuan.

Tourists from the Chinese mainland with valid ID cards and those from the Hong Kong and Macao special administrative regions who have entered the mainland with valid travel permits are eligible to join the tour during the trial operation, according to Zhuhai Customs.