Now, Copenhagen. Walking around on the city on a Saturday evening just after I arrived, I came across a round tower in the city centre. Inside, it looked like this:
A smooth brick floor curves resolutely to the top of the tower. Some soft evening light shone through the windows.
Of course, I discovered once I got to the top that the Rundetaarn was once an astronomical observatory, built in 1642, thirty years before the Paris Observatory. Peering through a window near the top one can see instruments and telescopes. Today, the centre of Copenhagen, like the center of Paris is no longer an ideal location for observations, at least of celestial objects.