111 20 Stockholm, Sweden
Stockholm Tourist Center arranges guided tours, sells tickets to most events, and books hotels. Buy the Stockholm Card here and get free entrance to 80 museums and attractions, free public transport rides, free or discounted sightseeing tours (most of them are available in the summertime) and a 192-page guidebook with maps. Or buy the 'kulturarvskort' card if you are staying for long, as its validity extends for one year. It also gives discounts in some museums shops and cafes.