84 Rotterdam Crowd sourced local archives for collective memories The Netherlands DIG IT UP in Rotterdam is a formalised cultural heritage collection process to enrich the city’s historical archives through crowdsourcing. Despite the large collection of the Rotterdam City Archive (Stadsarchief Rotterdam) - one of the oldest in the Netherlands and part of the municipality – part of the city’s intangible heritage was overlooked by formal government records. Memories, stories and oral traditions were at risk of oblivion as citizens were not sufficiently involved in heritage collection, preservation and dissemination. The collaboration between the grassroots cultural heritage organisation DIG IT UP, an organisation that seeks to excavate and exhibit Rotterdam urban culture, with and for the Rotterdammers, and the Rotterdam City Archive enabled a formalised cultural heritage collection process involving local communities to enrich the city’s historical archives through crowdsourcing. Citizens were able to record, describe, and give context to elements of collective urban culture and identity. The practice was introduced to different groups, communities and individuals in Rotterdam, who collected videos, photos and audio. The conservation and preservation of the inhabitants’ cultural heritage is assured by the collaboration with the city archives. A municipal archive cannot keep track of all that is happening across the city; but with the support of DIG IT UP, they can do it better and be as relevant as possible to citizens of Rotterdam. What?