Vondelpark has a found fence. If you find something in the park, clip it to the fence. I did an inventory.
2 pieces of candy in wrappers
1 note from tourists saying they love Amsterdam
3 sets of keys
1 piece of cardboard approx 1"x4"
1 thing you put around your neck to hold ID
2 businesses cards
1 hotel swipe key
1 fluffy red thingy
1 blue plastic wearable thing