The demolition, carried out by the Hue Military Command, began on Thursday and is expected to take 60 days, with completion scheduled for September 30.
The structures include 25 bunkers, three shelters, two guard posts and one observation post with an anti-aircraft position. Built for military purposes between 1957 and 1975, the reinforced-concrete structures have deteriorated over time, leaving cracked walls, damaged roofs and unstable foundations that pose safety risks.
Authorities said the structures are no longer in use, and their removal will facilitate restoration of the citadel's historic landscape while supporting long-term conservation and enhancing the site's cultural value.
The demolition follows surveys and inspections carried out by the Ministry of National Defence, the Hue Military Command and relevant authorities in October 2024, before a demolition plan was approved.
About 50 military engineers, supported by specialised equipment, have been deployed for the project. Authorities said the work would be carried out safely, on schedule and in compliance with environmental protection and heritage conservation requirements.