The gates may have been an escape route for the royal family of the Nguyen Dynasty, researchers say.
The citadel, a UNESCO world heritage site in the town of Hue in Thua Thien-Hue province, was home to the Nguyen Dynasty, Vietnam’s last royal family.
One gate, situated to the right of Luong Y Bridge, is 80 cm wide and 100 cm high. The brick floor beneath the bridge arch is still intact.
The other gate, situated to the left of Luong Y Bridge, sits behind a house built decades ago.