The greenbelt is a long area of recreation along both sides of the Boise river, a walking or hiking path that extends for miles. You can start anywhere and end anywhere. Brooke and I have mostly ridden our bikes for longer distances, but we have also used electric scooters and walked. Bike rentals are available at https://www.greenbeltebikerentals.com
Along the Greenbelt on the north side of the river you can enjoy Quinns pond, paddle board, swim, walk around and enjoy the outdoors. You can easily rent paddle boards at Idaho River Sports https://www.idahoriversports.com/pages/boat-and-board-rental-at-idaho-river-sports