If your idea of a fantastic vacation means being by the water, visit Munkholmen. No matter what you choose to do here, you're unlikely to get bored of those pretty views.
Trondheim City Centre, where Munkholmen is located, is full of interesting things to see and do. Many visitors also stop by Nidaros Cathedral, which isn't far from the water-surrounded land mass. See what it's about before you call it quits for this area.