Hiking to the Opabin Prospect will afford you the grandest vista in the Canadian Rockies! The Lake O'Hara Valley and its surrounds are nothing short of magical!
Located in Yoho National Park, Lake O'Hara is said to be the crown jewel of the Canadian Rockies (rightly so!). Callum Snape has described a bit of the process on what it takes to gain access to Lake O'Hara at this post here.
Once you arrive at Lake O'Hara, either at the lodge or at the neighboring campground, you will have SO many choices for adventures to pursue. At some point during your stay, be sure to make the Opabin Prospect a priority. Though it can be done along the way on a number of other hikes in the area, the most direct route is to hike up the West Opabin Trail, passing by Mary Lake along your way. Once you have taken the view in and had your fill of photos, you can continue on to another hike in the area or head back to the lodge/campground the way you came or down the East Opabin Trail, depending on how much time you have at this phenomenal specimen of the outdoors.