Statues featuring the Three Kingdoms (AD 220-280) warriors.

Last year the Shu Road was put on a list of candidates for UNESCO world heritage classification. Of the 3,700-square kilometer core road area, more than 2,000 sits in Guangyuan.

It needs to be said that this climb is not for the faint hearted, and dexterity with both hands and feet is needed in climbing some sections of the road because some inclines are nearly vertical, and the rough-hewn steps are very high, necessitating the help of iron chains on the side that you can grasp.

Even today, certain parts of the road can only be mounted aided by manual effort. A middle-aged man hiking along with us carried a big bamboo-braided basket of sand on his back.

"It's 100 kilograms a basket and I get paid 40 yuan ($6) a time," the man says, taking a break to catch his breath. The sand was intended for building work in elevated areas, he says.

As we continued our ascent, historic buildings began to appear. One of these is a lookout tower that has been rebuilt several times, most recently after the Wenchuan earthquake in 2008.