I don't think this is the backside of Castle Mountain. [The peaks and spires in this pic don't look like anything you see from Rockbound Lake] (https://images.squarespace-cdn.com/content/v1/5affa4dbe17ba31aab6cf10f/1560487696926-HLJFIKQFR7EN5PHDCIMG/RockBoundCal02FB.jpg?format=1500w) nor do they have the flattop and rather vertical rock faces that much of that mountain possesses.

The Spiral Tunnels and Wapta Falls are cool sights and low efforts off the highway, and Emerald Lake is the most popular attraction and pretty much Yoho's answer to Lake Louise.

But the two spots I'd recommend the most are the Lake O'Hara area , which is absolutely spectacular (if you're lucky enough to get a spot reserved since they limit visitors), and the Takkakaw Falls area.

Also if you're really into Earth's history the Burgess Shale is a fascinating fossil deposit that you can access via a guided hike.