Halloween dance cruise aboard M/S Birka Gotland, sailing Stockholm–Mariehamn–Stockholm. Departure from the Viking ferry terminal at Stadsgården on Friday 6 November at 17:30, returning Saturday at 14:30, all Swedish local time. Three dance floors feature trance, techno, psy, hardstyle, hard-dance and crossover music. Halloween costumes are encouraged but optional. Minimum age is 20 on boarding. Cabins start at SEK 1,423 per person, including fuel and climate fees; food, drinks and onboard shopping are extra. Standard four-person cabins must be filled; limited two-person cabins are also offered. Phone bookings incur a SEK 50 service fee. Tickets: https://www.vikingline.se/monday-bar. Current lineup: https://www.mondaybar.com/lineup-halloween-cruise-2026.