Located along the Perfume River, many relics of the Nguyen Dynasty in Hue including the Imperial Citadel, a UNESCO heritage site, have been submerged.
Heavy rains as an impact of Storm Son Ca poured down the central region from Friday night, with Thua Thien-Hue Province among the mosst affected areas.
The province, home to the former imperial town Hue, recorded rainfall of 500-600 mm from Friday night to 8 a.m. Saturday.
Nghenh Luong Pavilion next to the Huong River is submerged by 0.5 meters.
The pavillion is one of two relics in the ancient capital of Hue to grace the VND50,000 ($2.16) bill since 2003. The other relic printed on Vietnam's VND50,000 banknote is Phu Van Lau, Pavilion of Edicts.
Many roads around the Imperial Citadel are flooded for more than half a meter.
Built under King Gia Long, the first Nguyen ruler, the citadel was the power center of Vietnam's last royal family (1802-1945).
Some foreign tourists try to enter the citadel despite the floodwaters.
Tickets to the Imperial Citadel cost VND200,000 ($8.29) for adults.
Le Thanh Ton Street inside the citadel is submerged for nearly one meter, forcing residents to travel by boat.
About 100 meters from the citadel, Nguyen Chi Thanh Street in Gia Hoi Ward has also turned into a river.
Downstream the Perfume River, many houses in Bao Vinh Old Town in Huong Tra Town were flooded by about one meter.
Provincial authorities said over 19,000 houses in Thua Thien-Hue Province have been submerged under water.
The province has not recorded any casualties.
Heavy rains are expected to continue through Sunday.
