The site, located in Ma Pi Leng Village, Dong Van Commune, Tuyen Quang Province, will remain closed until further notice, local authorities said.
The closure will allow work to repair infrastructure, improve visitor safety and strengthen management and landscape protection at the attraction.
Authorities have urged visitors not to enter the construction area or attempt to access the rocky outcrop while the upgrades are under way.
The viewpoint, widely known on social media for its dramatic cliff-edge setting, has become a popular stop for travellers visiting the former Ha Giang Province.
Visitors can normally reach the area by motorbike before walking about 30-40 metres along a steep, rocky path to the outcrop.
According to local residents, the rock formation was created when a large boulder broke away from the mountainside due to weathering.