The suspension applies to the Thach Ban-Thien Thi-Phu Nghia trekking route, according to a notice issued to tour operators and visitors.
Park authorities said the route’s steep terrain, combined with heavy rain and slippery conditions during the storm season, posed risks to hikers.
The route has in recent years attracted large numbers of trekkers, particularly young travellers seeking to explore Tam Dao’s primary forest, rugged terrain and cool climate.
However, much of the route passes through dense forest with steep and slippery sections, especially after rainfall. Some areas feature narrow paths, cliffs and hazardous terrain that increase the risk of falls and injuries.
Rapidly changing weather and thick fog can also cause hikers to lose direction, while long hours of trekking may lead to exhaustion, cramping and dehydration.
The suspension follows a recent incident involving Nguyen Tuan Anh, a 19-year-old student from Hanoi’s Dai Nam University, who went missing while trekking in Tam Dao with friends on April 19.
Local authorities launched an overnight search operation, joined by volunteer trekking groups from several northern provinces and cities.
After more than 36 hours missing, Tuan Anh was found safe beside a stream at an altitude of around 600 metres on April 21.