Denmark - Copenhagen - Round Tower spiral sepia

Darrell Godliman has added a photo to the pool:

From Wikipedia : "Instead of stairs, a 7.5-turn spiral ramp forms the only access way to the towertop observatory as well as the Library Hall and the Bell-Ringer's Loft, both located above the church. The ramp turns 7.5 times around the hollow masonry core of the tower before reaching the observation deck and observatory at the top, on the way also affording access to the Library Hall as well as the Ringer's Loft. This design was chosen to allow a horse and carriage to reach the library, moving books in and out of the library as well as transporting heavy and sensitive instruments to the observatory.

The winding corridor has a length of 210 m, climbing 3.74m per turn. Along the outer wall the corridor has a length of 257.5m and a grade of 10%, while along the wall of the inner core the corridor is only 85.5m long but has a grade of 33%."