By Xinhua Writers Chu Yi and Zi Qiang

KUNMING, March 26 (Xinhua) -- In a matter of seconds, Qian Yafen can easily locate the nearest vacant toilet on her cell phone.

"I downloaded an app, clicked 'find a restroom' and then they just came up, with pictures of nearby public restrooms, numbers of available toilets as well as maps showing how I could get there," Qian said.

She picked the nearest one and scanned a QR code on a tissue box after entering the restroom, which distributed free toilet paper.

"It's brilliant! It helps avoid waste and solves my problem so quickly in a way that I'd never thought of," she said.

Qian is visiting the Old Town, a famous UNESCO World Heritage Site with an 800-year history in the city of Lijiang, Yunnan Province, which attracted more than 14 million tourists last year.

"The Old Town is so charming. I love it, especially its fabulous lavatories -- I even took pictures with them," she said.

All 30 public restrooms in the Old Town are two-story buildings with traditional characteristics of Naxi, the native ethnic group. Two LED screens hanging at the entrance of each restroom designate both the men's and women's room as well as a unisex room. The screens also display the real-time temperature, humidity, and the concentration of hydrogen sulfide and ammonia gas.

"You can check the availability of each toilet on the screen," said He Tang, a senior official with the protection and administrative bureau of Lijiang Old Town.

"We use simple figures with numbers below to represent each toilet on the screen. Red means occupied while green stands for vacant," he added.

According to He, a deodorization system has been installed, and the real-time monitoring of hydrogen sulfide and ammonia gas on the LED screen reflect the restroom's air quality.

"Lavatories are related to our most basic need. We want to give visitors a five-star experience in the Old Town, and public restrooms cannot be left behind," he said.

Since 2015, local authorities have invested more than 20 million yuan (about 3 million U.S. dollars) in renovating and maintaining public restrooms in the Old Town. Urine data such as sugar level is expected to be introduced in the future.

These public restrooms are the epitome of the ancient city's digital development.

There are 380 high-definition cameras working 24 hours in the Old Town to monitor public security, fire safety and other emergencies, the contents of which are accessed by local police stations and firehouses.

"Facial recognition will be added into the system within the year," He said.

The monitoring system could also indicate real-time visitor flow so tourists can easily check whether the scenic area is crowded on 13 digital information screens in the Old Town or on its official WeChat account.

Two first-aid stations have been providing services at the Old Town since last year. Scanning a QR code or the ID card, one could get Automated External Defibrillators, stretchers, wheelchairs, bandages and other medical supplies for free.

Meanwhile, local authorities have implemented a noise control system which will cut off the electricity to a bar if its noise exceeds 85 decibels ten times.

"Digital integration is an inevitable trend, which could make the ancient city more attractive and contribute to sustainable development of its tourism industry," He said.