Rotterdam will be hosting Rotterdam Rooftop Walk (official website in English) from 26 May through 24 June. It reminds me a bit of New York City’s The High Line, except on a smaller scale and for a limited duration.
Here is an artist’s impression, from the official website:
Note the temporary bridge connecting the two buildings. It looks pretty high up to me!
The tickets are €3.50 for adults, with kids entering free. There are also tours and other events going on between 3 June and 5 June, during the Rotterdam Rooftop Festival. The organization also has a live stream set up so you can watch the construction. To be honest it might just be a cool to look at the city itself, even without the rooftop construction going on!
Life in the Hague 