The best terrain I've ever ridden a bike on was a well-paved path of little resistance over forrested dunes. You start on top of a dune, pedal a little on the w

The best terrain I've ever ridden a bike on was a well-paved path of little resistance over forrested dunes. You start on top of a dune, pedal a little on the way down (not a lot of effort) and arrive on the top of the next dune with nearly zero speed. Perfect coasting and a cool breeze most of the time.