Besides pro-marijuana speakers such as Seattle mayor Mike McGinn, Washington state senator Jeanne Kohl-Welles and Seattle-based physician and medical marijuana provider Dr Gil Mobley, guests can expect music from the likes of Klover Jane, Human Revolution and the Highlife, as well as food, information booths and shopping (think hemp goods and pot-related accessories).

BBC: Rise of the tourist-friendly ganjapreneurs

World Cannabis Week: held in Denver between 17 and 21 April this year, the event includes such activities as a pro-marijuana rally, a weekend concert featuring the bands Slightly Stoopid and Cypress Hill, and a High Times Cannabis Cup, where judges sample and vote for their favourite marijuana strains and products.

BBC: Rise of the tourist-friendly ganjapreneurs

Technology enlarged the market, not just geographically by lowering transport costs but also by making possible the trade in a whole range of goods that didn't exist before, such as pirated software or genetically modified marijuana.

NPR: Tracking the World's Black Market: 'Illicit'