An opportunity for 6 people to explore Alewife Brook and the Mystic River by bicycle with Will Brownsberger. Take a leisurely group ride to the Amelia Earhart Dam and back, enjoy the rugged urban beauty of the Mystic, and visit and learn about key flood-control structures. Finish with lunch in Davis Square. Any bike is fine: None of this ride is steep or treacherous, but some of it is on dirt roads, so dress appropriately. Roughly 3 hours including meal. Helmets required. Not recommended for children under 10. This item has 6 spots available and they're sold individually. Date by mutual agreement: May to June is best.