We only stayed in Hue for one night. We arrived on the Wednesday at midday and then straight away did a half day bus tour. We went and visited some of the main emperor tombs which were really cool and pretty and then we took a boat down the river back to the town.
The next day we went and visited the citadel. It is the ruins of the main city of hue where the emperor used to live. It's been slightly restored for tourists but it was interesting to learn about and walk round. In the evening we caught an overnight bus to Ninh Binh.