Perhaps one of the most mysterious and least understood ecostystems on Earth exists right beneath our feet: Caves. These complex, ever-evolving systems are as diverse as they are extraordinary, supporting everything from highly specialized lifeforms to rare gems and minerals. The pristine and delicate nature of these underground worlds keeps many caves under restricted access, with the exception of research and exploration. Here’s a glimpse of a few subterranean wonders not too far from home.

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  Cara Kropp aides in lighting bizarre ice formations within a hidden cavern in nearby Cascade Canyon.

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  Beginner cavers from the Salt Lake Grotto poke into a beautifully sculpted stream course in Utah’s longest cave, which sports nearly 6 miles of surveyed passage.

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  A delicate gypsum flower sparkles under the glow of a headlamp.

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  Living cave formations, or speleotherms, as they’re known, are a rare and special sight.

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  Sometimes it requires a number of people to help illuminate underground passageways for photographs, as demonstrated by local cavers Crit Salaz and Pete Tschannen.