Take a look at this 15.4-kilometre circular path near Golden, Colorado. Finishing this fairly difficult course takes an average of 4 hours and 16 minutes. This is a popular trail for camping, hiking, and jogging, but you may still find peace during the day. This route is best visited between May and October. Dogs are permitted but must be kept on a leash.

Photos: Google Maps, Nicole Antonic; https://www.alltrails.com/