Wapta Falls in Yoho National Park is an impressively wide waterfall surrounded by mountains. There are several viewpoints at the end of the trail, or you can follow a rougher trail down to the shoreline of the river.

In the summer, the return hike is 3.2km. The trail is mostly flat, with some steep sections near the end. It takes just over an hour. The hike is longer in winter (4.8km), with the trailhead being situated right on the highway instead. Allow 2-3 hours for the return trip.
While Wapta is well known and easily accessible, I have marked it as 'off the beaten path' as it is usually pretty quiet. This is particularly true in winter.

A Parks Canada parks pass is required to hike to Wapta Falls ($22/day for a vehicle of up to 7 people).