In the summer of 1661 he vacationed with Ole Borch and visited the Zuidersee and the university town of Groningen.
From Rostock he would have gone on to Hamburg, where he would have undoubtedly seen the cathedral and perhaps the Spinnhaus and the Zuchthaus.
From Dunkerque Niels Steensen could see England, a country he was never to visit. On his visit he would have seen this belfry, which still stands today.
In the summer of 1663 Niels Steensen travelled to Belgium, and visited Antwerp, Louvain, Gent, and Dunkerque. This picture shows the town hall of Louvain. After his holidays Niels Steensen returned to Leiden, and in early 1664 went home to…