This is easy to climb as there are no steps until the very top where you have a great view of the entire city and Sweden across the water on a clear day
Nice tower with an interesting gallery inside at the moment. Really good view from the top. Look for the small hole in the wall to find a glass bottom and see all the way down.
Europe's oldest functioning observatory. There has been looked at stars since 1642 from this place. It's a long walk up but if no clouds, a great place to look around. ("360 degree view").
Great place to visit one of your first days in Copenhagen because you get a nice view from the top. Also very nice walk up the spiral tower with many historical notes and a small exhibition.
Built in the 17th-century it began life as and continues to serve as an astronomical observatory. More recently, it has become a historical monument and observation tower.
Fun for a sunny day, simply because you'll see more when you wearily reach the top. Be wary of children running down as you're on your way up. Some of them are chubby and unstoppable.