Angel's Window at Cape Royal.
The next day we got up very early and headed for Roaring Springs. Roaring Springs is over 3000 vertical feet down one of the side canyons and a 4.7 mile trip one way. From the trailhead it is the farthest you should hike into the Canyon if you don't plan on staying overnight. The guide books and visitor information recommend you leave no later than 7:00am if you hope to return in a single day. The trail starts at more than 8000 feet and descends through switchbacks into the Canyon. This pretty rock formation adorned by a couple of trees caught my eye as we descended into the Canyon.
Andra at Supai Tunnel (2.7 miles from the trailhead). There was no practical route here, so they just bored through solid rock.