The Dutch have an attitude of tolerance dating back to the 16th century when they forced out the Spanish and their inquisition. Since then, they have chosen not to make an outrage out of victimless crimes like prostitution, homosexuality and the use of soft drugs, although the stance has been changing slightly in recent times.
This permissiveness has resulted in Holland becoming a Mecca for those who wish to experience the freedom of the adult entertainment and cannabis cultures. The coffeeshop is an unique Dutch institution. For over 20 years, coffeeshops have operated and there are approximately 300 shops in the city where you can buy and smoke canabis.
However, the smoking ban has an effect on the coffeeshops and soft drugs scene, although many of them have catered to customers needs by creating smoking rooms... If you don't smoke, but would still like to be involved in the soft drug scene, try spacecake.
More recently, the government also introduce a rule which banned the selling of magic muchrooms. Most smart-shops-owners are still fighting this law, but as yet, they have failed to have it overturned.