http://www.nytimes.com/2016/09/27/world/asia/korea-china-baekdu-changbaishan.html :
CHANGBAISHAN, China — The thick fog that had enveloped the mountain all morning suddenly dispersed, unveiling a crater lake of emerald water and setting off a buzz of excitement among the hikers gathered at the summit.
“I can see it! I can see it!” some shouted.
Park Jae-hee, 50, a South Korean author who in the fog of morning had climbed the mountain, known as Baekdusan in Korean and Changbaishan in Chinese, took a few tentative steps toward the cliff overlooking the lake, her eyes misting over.
“The moment I saw it, I felt like choking up, fighting back tears welling up in my eyes, something hot coming up from my heart,” Ms. Park said. “Only Koreans will understand how I felt.”
At 7,185 feet above sea level, the 3.8-square-mile caldera lake, called Cheonji in Korean and Tianchi in Chinese, was created a thousand years ago in one of the biggest volcanic eruptions in history.
Like Loch Ness in Scotland, the 1,260-foot-deep lake is also home to amythical monster. People in China have reported sightings of giant seal-like or scaled and horned creatures swimming in the lake, though scientists say the water is too cold for large animals.
But for Koreans from both North and South, Cheonji and the 9,029-foot-tall Baekdusan are much more than natural wonders. They are viewed with a near-religious reverence and are considered the spiritual home of their respective nations.
North Korea sends party cadets and soldiers on pilgrimages to the mountain to swear their loyalty to their leader, Kim Jong-un, who claims to be of a “Baekdu bloodline.” The lake also looms large in the North’s propaganda. When Mr. Kim’s father and predecessor, Kim Jong-il, died in the winter of 2011, the North Korean news media claimed that the thick ice on the lake cracked “so loud, it seemed to shake the heavens and the Earth.”
In South Korea, the national anthem opens with a reference to Baekdusan, and walls of government offices are decorated with panoramic pictures of Cheonji. Baekdusan regularly tops lists of places South Koreans wish to visit before they die.
But for decades after the Korean War in the early ’50s, which ended with Korea divided by a sealed border, South Koreans were barred from visiting by North Korea and China, the North’s Cold War ally. Under their 1962 border treaty, North Korea and China each owns roughly half of the mountain and Cheonji.
The door opened only in 1992, when China and South Korea forged diplomatic ties.
South Koreans began rushing to Baekdusan, climbing the Chinese slopes of the mountain. Barring the reunification of the two Koreas or a sudden decision by the North to open a land route across the Korean Peninsula — both prospects distant, given high tensions on the peninsula — the route through China is the only way for them to visit their “holy mountain.”
That devotion has not been without problems.
Once on the mountaintop, many South Koreans are moved to display theirnational flag, chanting hurrahs with arms raised, and singing their national anthem — raising the hackles of North Korean border guards nearby. In 2008, a cast of celebrities in a popular South Koreanreality TV show traveled to Baekdusan with bottles of water collected from remote corners of South Korea and poured them into Cheonji in what they called a symbolic gesture of making the divided Korea whole again.
Today, local guides, mostly ethnic Korean-Chinese, recite a strict Chinese government ban on such activities.
“Please no national flags at the top,” one of them said. “This is not your Mount Everest.”
The stunts have largely come to an end in recent years, with many Chinese national park officials around at the scene to enforce the ban.
“There is something about Baekdusan that makes all Koreans patriotic,” said Lee Byong-chul, senior fellow at the Institute for Peace and Cooperation in Seoul, who visited the mountain last year with a group of former South Korean government officials and scholars. “There, Koreans feel they have come to their roots.”
Planes from South Korea usually land in Yanji, the seat of the Yanbian Korean Autonomous Prefecture in northeast China, which is home to a large ethnic Korean community, most of them descendants of Koreans who fled Japanese colonial rule in the early 20th century. In Yanbian, all store signs are both in Chinese and Korean. The South Korean won is as welcome as the Chinese renminbi.
In Yanbian, the South Korean tourists visit historic sites linked to Korean patriots who fought for national independence from Japanese colonial rule or to ancient kingdoms in northern China that Koreans see as part of their history.
While they are not allowed to go near their own country’s heavily armed border with North Korea, South Koreans in Yanbian can also gaze at the North lying just a stone’s throw away. In Tumen, a town on the river border with North Korea, tourists from the South take pictures of themselves with the North as a background.
Across the narrow river, Mr. Kim’s late father and grandfather, Kim Il-sung, who had ruled before him, smiled from large portraits hung on a riverfront building. Behind them, the North Korean town of Namyang slumbered in decrepitude. Little human activity was visible.
“Taking pictures, throwing items or shouting to the North Korean side is strictly forbidden!” read a sign posted in Korean by the Chinese authorities, a warning to the Korean tourists who take $20 boat rides down the river to get closer to North Korea and are known for throwing food and dollars to North Koreans.
Park Jong-ae, 29, who is Korean-Chinese and makes a living guiding South Korean tourists to Baekdusan, said recent warnings by the South’s government of possible terrorist attacks by the North have reduced the number of South Koreans traveling to Baekdusan. These days, a vast majority of people disgorged from a fleet of buses or 10-seat Mercedes vans to hike the last short stretches to the mountaintop are Chinese, she said.
Ms. Park, the author, said her country’s recent tensions with China over the South’s decision to deploy an American missile-defense system — and rumors that China might tighten visa restrictions for South Koreans — prompted her to hurry.
Besides, she was embarking on a new career as a travel writer. She wanted Baekdusan’s blessing.
“The older I got, the more I wanted to visit Baekdusan,” she said. “So I hurried before it gets too late. There is no guarantee that I can come and see Cheonji again before I die.”