Others said it makes for a nice stop along the Red Rock Scenic Byway (the chapel is located at the byway's north end). If you're planning to take one of the best tours in Sedona, you'll find that ...
head about 11 miles south of central Sedona. The byway starts after you take exit 298 off Interstate 17. If you only have time for one cultural site, the Chapel of the Holy Cross should be it.