Outdoor escape game by Outside Escape โ not a physical escape room, but a puzzle route through Alkmaar that you play at your own pace with an envelope full of tasks and your phone. At the statue of fortification engineer Adriaan Antonisz in Alkmaar, a mysterious old map surfaces pointing to a hidden underground gunpowder store from the time of the Eighty Years' War. Players follow the clues on the map and solve puzzles along the way to find the location.