Just look at the above picture of new Observation Tower which you can now visit in Denmark. The above design is made by Danish architecture firm EFFEKT. The construction of this treetop was declared in 2017 and had to open in the summer of 2018. So, I think the construction of new observation tower would have been finished and public visit would have been started.
This observation tower is located in south of Copenhagen, Denmark, which you need one hour to reach their. First you will have to start your journey through the forest of Gisselfeld Klosters Skove where you can travel around and study various things. The forest also offers various places where you can relax for a while.
148 ft tall observation tower has the continuous wood ramp of 1970 ft long to go top of the tower to have a 360 degree view.
The structure of tower is made of weathering steel and the ramp that helps you reach its top is made from timber collected from the nearby forest. Go and enjoy the wonderful view from the top of the tower.
The middle portion of the tower is very slim while the base and top are the largest. The shape of the tower organically perfect with the forest canopy.
Source: http://www.contemporist.com/denmark-observation-tower/