The Rokin archaeology display holds about nine and a half thousand objects pulled out of the bed of the Amstel, and not one of them was put there on purpose. Between 2003 and 2012 the river was drained and dug out to sink the metro line, and the city's archaeologists went through the spoil. They recovered 697,235 items in all: keys, pins, knives, coins, clay pipes, cutlery, shoe buckles, mobile phones. A river ran through the middle of the city for centuries and people dropped things into it the whole time.
The selection on show fills two long glass cases beside the escalators, eighty-four panels in all, sorted into ten themes of city life such as light, games and communication. Nothing was picked because it was important, so a medieval dagger sits near a 1990s collector's disc, and a stone arrowhead near a tram ticket. There are no labels under the individual objects; every find is photographed and described in a public online catalogue instead. The cases stand inside a working metro station.