Crowd2Map Tanzania is a crowdsourced mapping project putting rural Tanzania on the map. Since 2015, we have been adding schools, hospitals, roads, buildings and villages to OpenStreetMap, an open source map available to all, with the help of over 12,500 volunteers worldwide and 1600 on the ground in Tanzania. With minimal budget and no staff we have so far added over 4 million buildings and trained community mappers in 26 areas of Tanzania in mapping for community development. We have helped set up Youthmapper chapters in 7 different universities in Tanzania and given training to many different community groups. Having better maps protect girls are who are at risk of FGM by helping activists and the police better find them. We are now starting mapping informal border posts to help prevent cross border trafficking. The mapping is in two phases – firstly online volunteers trace roads and buildings from satellite images such as in these tasks then volunteers on the ground add names of villages, clinics, offices, churches, shops and other points of interest using a free smartphone app Maps.Me. We were invited by UNFPA to organise an FGM mapathon as a United Nations General Assembly side event in September 2018, and a concurrent global mapathon with events in 60 countries. We will also be holding a mapathon at the Nairobi Summit to mark 25 years since the Cairo Declaration on empowering women. Please get in touch if you want to know more and/or get involved!