By: Katherine Gustafson
- Castle Hot Springs is one of the top resorts for guided stargazing in Arizona, offering astronomer-led viewing of the Milky Way from geothermal pools.
- Guests at Castle Hot Springs enjoy 24-hour access to pools set at three different temperatures where they get a unique experience under the Arizona night sky.
- Arizona is among the darkest places in the U.S., giving visitors the chance to see bright stars without light pollution in a desert landscape.
Picture it: You’ve just eased into the steaming mineral water at Castle Hot Springs. The desert night is dark and crisp, and you lean your head back with an exhale. You gaze upwards, and there it is: an endless sky thick with stars. The Milky Way flows overhead, a glistening silver-white river, while the water flows around you as it rises hot from the depths of the earth.
There is no comparison for a dark Arizona night sky experienced from a geothermal soaking pool. This is the transformative moment Castle Hot Springs guests come from around the world to experience — a profound immersion in natural grandeur and stunning sensation that is hard to find anywhere else.
Arizona’s Skies Are Different
Searching “stargazing near me” in most American cities is an exercise in disappointment. You might find an urban park where you can see a star or two as you squint against the streetlights. Or directions to a remote field brightened by an orange haze on the horizon. The physics of the modern world is hard on stargazers, as artificial light diffuses upward and outward for miles. About a third of humans, including about 80 percent of people in North America, can’t see the Milky Way from where they live.
Arizona is the exception: Anyone hunting for the darkest place in the U.S. will find the state at the top of the list. DarkSky International, a recognized worldwide authority on fighting light pollution, has recognized around 20 places in Arizona where darkness is preserved, one of the highest concentrations in the country.
Decades of policymaking to address light pollution have made a huge difference here, as do the dependable clear weather and high desert elevation. The result is night skies that look a lot like they did a century ago.
Castle Hot Springs is perfectly positioned to take full advantage of this unique situation. Sitting inside a secluded canyon beneath the Bradshaw Mountains in the Sonoran Desert, it is just over an hour from Phoenix but a world away from the city’s fluorescent glow. The resort’s carefully planned, downward-shielded lighting throughout the property ensures that visitors can see the stars without light pollution, bringing them close to a sky so unfiltered its brightness can seem unreal.
And with over 300+ days of sunshine Arizona experiences little cloud-cover making for optimal viewing of clear night skies. It’s remarkable to view the grandeur of the Milky Way with high visibility and brightness in every direction.
Soaking Under the Stars
Stargazing at Castle Hot Springs is unique because it’s best done from restorative warm pools that are open all night. The geothermal water flows through three pools of different temperatures, the hottest reaching up to 108°F. The 24-hour access means you can come to stargaze any time that works for you, including in the darkest hours of the night when the sun is long gone and your eyes have fully adjusted to the celestial world.
It’s a magical experience to soak in water so warm you may get drowsy while peering into the vast coldness of deep space. The relaxation and stillness of the water can make the huge sky feel closer than normal, while the scale of the heavens gives the soaking pool the feel of a cozy, private refuge.
Guided Viewing With an Astronomer
Castle Hot Springs offers monthly guided sessions with a professional astronomer for guests who want to go deeper into the stargazing experience. Participants get to peer through high-powered telescopes to see Saturn’s rings, the star clouds of the Milky Way, and the Andromeda Galaxy, which remains hidden from the naked eye under lighter skies. This option is why Castle Hot Springs ranks among the top resorts for guided stargazing in Arizona.
Among stargazing hotels in Arizona, and even among stargazing resorts in the U.S., Castle Hot Springs stands apart due to its ideal location in a dark, protected canyon and its variety of locations from which to view the stars. Sky View Cabins come with elevated decks built for stargazing, and the pools are the best seat in the house.
Dark Sky Canyon
Experiencing a sky as dark as it appears at Castle Hot Springs is rare. Light pollution in night skies around the world increased by as much as 10 percent every year between 2011 and 2022, accompanied by a rapid decline in the ability to see the stars. The chance to see the Milky Way is fast disappearing, and few places exist with the right conditions to preserve this capability.
Castle Hot Springs happens to enjoy those conditions, and so its guests benefit from much more than just a soak in some warm pools. They are able to experience both geothermal heat and extraterrestrial wonder in one singular experience: Any time of night, you can lie back in the steaming water under the celestial show.