For the last 31 years, thousands of students in Northwest China have marked the approach of Qingming Festival, or Tomb-Sweeping Day, with an extraordinary act of remembrance: a 54-kilometer trek through rugged mountain terrain to honor fallen soldiers.

At 5 am on April 3, more than 3,000 participants set out from Guyuan, Ningxia Hui autonomous region, to embark on a journey to the Renshanhe Martyrs Cemetery in neighboring Pengyang county. The round trip spans roughly 17 hours and has become a powerful annual tradition described as a "walking ideological and political class".

First organized in 1995 by students from two local middle schools, the memorial has since grown into a broad community effort. This year's participants included not only students but also young volunteers and over 700 people from all walks of life, according to the local authorities.