While not on the coast Hue is very close to the beach and it is possible to take a day trip to the coast and enjoy the beach, it is a pleasant rest for the feet after all that walking.
The area around Hue was some of the most fought over territory during the Vietnam war and you can visit some of the battlegrounds and tunnels from the war on a day trip, there are also various museums and displays in Hue
A peaceful way to enjoy the city is a dragon boat cruise along the Perfume River, float along between the new and old parts of the city and take in the views.