Kattegat is an age-old name that seafarers used to sail from the eastern part of Denmark. Its not really a place name and it is not located in the Netherlands. Kattegat is a beautiful holiday destination. In other words, the area around Kattegat. Kattegat is the sea between the east of Denmark and the south-west of Sweden.The name comes from Dutch Sailors. They called it Kattegat because it had a narrow passage. This refers to the fact that a cat could crawl through very narrow passages. Fun fact: the Germans, Danes and English also use the name Kattegat. (source: Google Bard)