The Foroglio waterfall (110m high) is the most spectacular in Ticino. Located in the Bavona Valley at the top of Maggia Valley, the waterfall and the gracious stone village only few steps away are of a rare beauty. You can spend few hours climbing the rocks of the waterfall or along the river, and enjoy a picnic with a fantastic view. The beauty of this place attracts tons of tourists, so in order to avoid crowds and feel the peacefulness of the spot, you should better go during the week or very early on the weekends. It is my understanding that this place is not accessible during winter.
https://goo.gl/maps/4tZpVMnMWs8kcsRMA
https://www.myswitzerland.com/en-ch/experiences/bavona-valley-and-foroglio-waterfall/
https://myswisspanorama.com/en/foroglio-2/