• Stay on the boardwalk, since leaving the paths is banned to protect fragile lichens and grasses, so leave the sand toys at home
• Short loop, longer options: the boardwalk alone takes 20-30 minutes, or make a longer walk of it with the Main ferry to Höchst and back
• Getting there: bus to Alter Friedhof Schwanheim, then about 10 minutes on foot; drivers park on Kelsterbacher Weg by the allotment gardens

Schwanheimer Düne is a 58-hectare nature reserve on an inland sand dune, formed from Main riverbed sand after the last Ice Age. A wooden boardwalk loops through pine trees, silver grass and open sand, with information boards. Kids have to stay on the boards to protect the lichens, which makes it a car-free stretch for running. Look for herons fishing in the Schmitt'sche Grube, a former sand pit.