For Hope Justman, an 82-year-old scholar who has explored several historic paths across the globe, the ancient road system shudao (road to today's Sichuan province) dating back over two millennia remains her favorite.

A resident of Philadelphia, Pennsylvania, Justman recently concluded her 25th trip on Friday along the shudao, or Shu Road, a path she first stepped onto in 2001.

Shu is short for Sichuan, and was its ancient name as well. The ancient Shu Road is a system spanning more than 1,000 kilometers, connecting today's Xi'an in Shaanxi province and Chengdu in Sichuan, over the Qinling and Daba mountains. It was built as early as 2,300 years ago.

This year, Justman and over a dozen of her friends embarked on a journey starting from Pu'an township in Jian'ge county. They passed through iconic landmarks of the shudao, including the Cuiyunlang Corridor, Jianmen Pass, Zhaohua ancient town and Mingyue Gorge, covering a distance of over 300 kilometers.

They also experienced local intangible cultural heritage and folk culture, such as Gaoguan shadow puppetry and Maliu embroidery.

Leading the group with a trekking pole in her hands, Justman shared the history of the Shu Road all along the way while noticing recent improvements.

"The newly added road signs, restrooms and parking spaces make it more convenient to hike here," she said.

In the Cuiyunlang section of the shudao, Justman was delighted to find that each ancient tree now has a QR code on its plaque, which, when scanned, reveals details such as its ID number, age and health status.

Local authorities said the Cuiyunlang section is home to 7,778 ancient cypress trees with an average age of 1,050 years, the oldest tree being approximately 2,300 years old. Each tree has an electronic ID and is cared for by dedicated workers.

Justman also visited the three cypress trees she had personally planted, loosening the soil and watering them.

Justman's fascination with the shudao began in her college days. At age 20, she saw a Tang Dynasty (618-907) painting titled Emperor Minghuang's Journey to Shu at an exhibition in Boston, Massachusetts, in which a plank road clinging to the steep cliffs left a lasting impression on her.

In 2001, she read an article about the ancient shudao and confirmed that the plank road was real, so she made up her mind to explore it.

"This place is exactly like the ancient painting — it feels as if I had stepped right into that painting," she said, standing at the Mingyue Gorge plank road.

Gazing at a swiftly passing train on the Xi'an-Chengdu high-speed railway in the distance, Justman marveled that the shudao, once described as "harder than climbing to the sky" by Tang Dynasty poet Li Bai, has become a smooth path.

Over the years, Justman has documented her hikes along the shudao through words, photos and videos. To share its story with the world, she has published a book, created a website and produced documentaries about it.

A San Francisco resident surnamed Chen, who joined Justman to visit the Shu Road for the first time, said she is surprised at its remarkable preservation and beauty.

"You can feel the locals' tremendous effort in preserving it," she said, adding that it has helped her understand Justman's determination to visit the ancient road.

Pu Huaping, Justman's old friend who is the vice-president of Zhaohua district's shudao and Three Kingdoms (220-280) culture research association, presented her with a Chinese calligraphy piece titled Migratory Bird of Shudao, symbolizing her enduring connection to the ancient roads.

Pu said he admires Justman's perseverance in exploring the Shu Road, noting that her efforts have raised its profile, and her insights and suggestions for its further preservation are invaluable.