Mallyan Spout drops around 70 feet down an almost vertical wooded ravine, and it is far more impressive after heavy rain. The classic circuit is roughly 3 miles (4.8 km), about an hour and a half, starting from the village, dropping into the wooded valley, following West Beck to the falls, then returning along part of the old Whitby to Pickering railway track bed via Beck Hole.
Be realistic about the terrain: steps, gates, mud after rain, and a rocky, awkward path along West Beck where the rocks are slick and the beck can run fast. There is scrambling in places. Boots, not trainers. Keep dogs under close control near livestock, which means most of the route.
Want something flatter and easier underfoot? The Rail Trail to Grosmont is about 3.5 miles along the old line, with ironstone mining history on the way, and it is a good one way walk if you can time a train back.