Lauren suggested we participate in Natuurwerkdag.
Natuurwerkdag is an outdoors volunteer event. This year, it's on 3 November and the idea is pretty simple: you go to www.natuurwerkdag.nl and find a volunteer site that looks good to you (typically a park), then you sign up, and you show up on 3 November ready to help prune trees, plant bulbs, paint stuff, etc. It's a lot of fun and I encourage you all to check it out!
Lauren, this event can be edited by all MeetUp members, so please take it from here and choose the time and location!