Stockholm
I also got time to visit the Vasa Ship . The ship was built for King Gustavus in 1626 and sank just 2 nautic miles on her maiden voyage (wikipedia). If no one had taken the job getting this great ship up from the bottom of the sea in the 1960’s it could at some point only be considered a legend that some people possibly would claim was not true. It is amazing how well conserved this wooden ship was even after 300 years at the bottom of the sea. This was at around the same time derivatives trading was quite active in Amsterdam, more and more sources of ancient derivatives literature are re-discovered.
As a Norwegian I am ashamed to say I know New York and London much better than Stockholm. After this trip I must say Stockholm now is one of my worlds favorite cities, it has so much to offer. I had been there before, but only on one-day business trips. The summer in Scandinavia is just fantastic!
Enjoy the summer (if on the summer side of the earth, if not fly there).

