BEIJING -- Some 20 kilometers southwest of Tian'anmen Square in Beijing, among the skyscrapers, speeding silver bullet trains, and a web of asphalt roads lies a patch of green.

Here, time seems to slow down.

A smoky-gray wall encloses a fortress-style town. Beyond its western gate, a stone bridge arches over the shimmering Yongding River. Also known as the Marco Polo Bridge after the Venetian traveler, Lugou Bridge had long been celebrated for its moonlit dawns.

Over the past week, footsteps echoed beneath the arched gates of Wanping, the old walled town, as waves of visitors came and went -- old and young, many from far away, in search of memory, not spectacle.

This year marks the 80th anniversary of the victory in the Chinese People's War of Resistance Against Japanese Aggression and the World Anti-Fascist War. It was from this very place that the whole-nation resistance began during that long and arduous struggle.

On July 7, 1937, with China mired in poverty and growing foreign encroachment, Japanese troops stationed on the outskirts of Beijing -- then called Beiping -- demanded entry into Wanping to search for a soldier they claimed went missing during a military drill.

Even as negotiations were underway, they opened fire on Chinese troops near the bridge and began shelling the town. Lugou Bridge occupied a key route in and out of Beijing at the time, making it a prime target when Japan launched its full-scale invasion of China.

The crisis awakened the Chinese nation. Regional resistance that had emerged since Japan's incursion into Northeast China in 1931 soon turned into a nationwide effort. People set aside whatever rifts they had and pointed their guns, blades and anything they could wield outward, fighting uncompromisingly until Japan's surrender in 1945.

Over the past 88 years, the land has changed beyond recognition -- cities have risen, borders have shifted, generations have come and gone. Yet, the Chinese people have preserved the town much as it was, with its shell-scarred walls standing quietly as a witness of the past.

Within those walls, they also built a large museum to enshrine items that carry this piece of memory -- a reminder of how the nation chose to stand united and fight in the face of an existential crisis. On Tuesday, after nearly eight months of renovation, the museum reopened to the public, free of charge and without the need for an appointment.

Among the visitors were veterans -- many in their 90s and wheelchair-bound. Some had started out as child sentries or message runners. One had worked as a cook, recalling how he once steamed buns to bring to the troops, only to arrive and find they had all fallen.

An Yangdong, a resident of Beijing, attended the exhibition in place of his father, who has passed away. "The hardship of that war is beyond what we can imagine today," he said.

In the combat during the early stages of the war, according to his father, it was often several of them against a single Japanese soldier. "They were professionally trained," his father had said. "We had barely any military training -- one day you might be a student, and the next, you were on the front line."

Chen Qingxiang, a 98-year-old from Cangzhou, North China's Hebei province, said he fought his first battle on his third day in the army. He and his peers were trying to seize a Japanese military truck. He fired two shots. "Our weapons were no match for theirs back then," he said.

After the Meiji Restoration in the 19th century, Japan became the first country in Asia to realize industrialization, leading to rapid expansion in its national strength. One photo on display at the museum captures a Japanese military plane brazenly flying over Beijing -- a chilling reminder of the disparity in power.

A trove of letters exhibited at the site reveals how Chinese people felt during that time. A person documented the atrocities he witnessed following the Japanese occupation of Beijing, pouring his grief over the war and the nation's fate into a letter for future generations. He hid it inside the iconic white pagoda at Miaoying Temple, which was under renovation at the time.

In others letters, a member of the Communist Party of China (CPC), writing before her execution, told her child she was dying for their country, a general vowed to fight to the death for the nation, and a young man bid farewell to his mother, heading to the battlefield with no expectation of returning alive.

Gao Hong, former director of the Institute of Japanese Studies at the Chinese Academy of Social Sciences, noted that Japan once believed China would collapse easily, based on the assumption that the country was fragmented at that time -- the Qing Dynasty (1644-1911) had fallen, and warlords were fighting each other.

"But once they pushed in, they realized they had unwittingly become the 'cement' -- binding that loose sand into concrete," said Gao. "To save their country, people fought against overwhelming odds. Every inch of land was, quite literally, soaked in blood."

When news of Japan's surrender arrived, Chen recalled, joy swept through the villages. Families of those taken to work as forced laborers or miners wept with both joy and sorrow. "They could not get their loved ones back," he said, "but finally, the invaders were driven out."

An's father was wounded during the CPC-led Hundred-Regiment Campaign in 1940, an injury that left him disabled for the rest of his life. "Those who love war will surely perish, but those who forget how to fight will face danger," he said.

Guan Yuhan, a sophomore at Capital Normal University and a volunteer guide at the museum, said the exhibition presents historical facts to the world -- a task that matters all the more at a time when unilateralism, economic coercion and hegemonic thinking are on the rise.

"Just as we're trained to always guide audiences forward," she said, "the items on display remind us of the brutality of war -- and how hard it could be to win peace. We must stay alert."

In recent years, politicians in some countries have sought to twist history for political gain. Observers have reported a troubling trend: growing attempts to whitewash Nazism, glorify Nazi collaborators, and revive the toxic legacies of racial discrimination, xenophobia and intolerance.

Until this day, some right-wing politicians in Japan still refuse to renounce the country's militaristic past, and even question or deny the outcomes of World War II.

"Many of the modern and vibrant cities the world sees in China today, such as Shanghai and Chongqing, were rebuilt from the rubble left by Japanese bombings and shelling," said He Husheng, a professor of CPC history at Renmin University of China. "China, now the world's second-largest economy, truly rose from scratch."

Throughout the war from 1931 to 1945, more than 35 million Chinese soldiers and civilians were killed or wounded. China suffered direct economic losses of over $100 billion and indirect losses exceeding $500 billion, calculated in terms of 1937 levels.

"The country's fortitude and tenacity, however, tied down a large portion of Japanese forces, disrupted Tokyo's strategic plans, and eased pressure on Allied fronts in Europe and across Asia," said He. "This proved decisive in the defeat of Japanese fascism."

Today, life in Wanping moves at a slow and peaceful pace. Restaurant owners warmly invite passersby to stop for a drink or a bite. On the Lugou Bridge, children run and laugh, playing among the stone lions that line the centuries-old structure.

To mark the anniversary of the 1937 event here, netizens shared homemade videos on social media.

In one, the screen was split: one half showed a baby sitting helplessly amid the debris in Shanghai, crying after his parents were killed in a Japanese bombing in 1937; the other half showed children of today resting atop the deck of a naval ship. The video also included additional footage of China's aircraft carriers.

"Eighty-eight years after the July 7th Incident," a comment read, "I doubt anyone dares to touch our children now."