Nice park, plenty og space, in the heart of the city. It's open on all sides - also towards a heavily-trafficked road, which makes it noisy and not as peaceful.
It's also a place where nearby schools and daycares show up unexpectedly.
Across the street from the main train station (and Odense hostel), the King's garden isn´t particularly large, but the tall old trees make create a peaceful atmosphere. Perfect for lying about and relaxing while you decide where to go next, or just for enjoying a bit of green before continuing your travels.