Destinations The Caribbean The 'Blue Heart Spring' in Idaho Is One of the State's Best-kept Secrets — With Gorgeous, Caribbean-blue Water Hidden by a Forested Passageway You'll need to rent a boat and find a hidden passageway to get to this oasis — but the crystal-clear waters are well-worth the effort. By Evie Carrick Evie Carrick Evie Carrick is a writer and editor who’s lived in five countries and visited well over 50. She now splits her time between Colorado and Paris, ensuring she doesn't have to live without skiing or L'As du Fallafel. Travel + Leisure Editorial Guidelines Published on April 17, 2023 When you think of an oasis of bright-blue water, Idaho probably doesn’t come to mind. But the state has long hidden one such site — and it's only accessible by boat.Idaho’s Blue Heart Spring is easily one of the most visually stunning natural springs in the U.S., yet it remains a mystery to most thanks to its hard-to-reach, water-bound location and cool temperature (to be clear, this is not a hot spring). To get there, travelers must paddle up the Snake River near the tiny town of Buhl, Idaho. Along the way, you’ll pass the Box Canyon confluence, where the cold, blue Box Canyon water visibly mixes with the Snake River water. Iamraffnovais/Getty Images Just past the outlet to Box Canyon, the Snake River bends to the west, while a small passage continues north, leading to a forested area. Once you boat through the passage, it opens up into the Blue Heart Spring — a quiet and serene space that’s surrounded by trees and lava rock. Iamraffnovais/Getty Images The crystal-clear waters of the Blue Heart Spring are shockingly blue. The water hovers around 58 degrees even on the hottest days, making it the perfect place for a midsummer dip. Whether you choose to swim or stay on your watercraft, make sure to peer through the clear waters to watch the sandy floor of the spring bubble as the water pushes up through the ground. The journey to Blue Heart Spring is best done by kayak or paddleboard, since boat engines are not permitted to run inside the oasis. The best launch point is near Banbury Rentals, which rents paddleboards and kayaks and offers guided day trips. It takes between 35 and 45 minutes to paddle from Banbury to the Blue Heart Spring passage. While Blue Heart Spring is still a lesser-known site, it is a favorite place for locals, so visit on a weekday to avoid the crowds — and be sure to pack out your trash. Just a couple miles west of Blue Heart Spring is Miracle Hot Springs, a geothermal hot spring that will quickly banish any chill that remains from your Blue Heart Spring dip. Miracle Hot Springs has four general admission pools, 15 private pools, and group soaking ponds. Overnight guests can choose from a series of geodesic domes, a home rental, and campsites. Buhl, Idaho, the closest town to both Blue Heart Spring and Miracle Hot Springs, is less than two hours from Boise, Idaho, by car.