Arizona   Kartchner Caverns State Park- Benson, AZ (outside Tucson) thank you to Bob and Connie from Wisconsin for this recommendation - not a hike but a cool, unique experience! a living cavern with beautiful cave formations - world's first wheelchair accessible cavern - tram to cavern is accessible - two paved trails through caverns (two seperate tours); each a little over .5 miles long - per website trail includes switchbacks and "some grades of up to 12%" on trails so it may not be appropriate for everyone - per website "wheelchairs with a seat width of 18" or less and an overall width of 30" are permissible"; see website for more detailed info - warning:  humidity level in caverns is 97 to 100% with an average temperature of 71 degrees- can feel very warm - The Big Room Tour is approx 1 1/2+ hours long - lots of accessible parking, restrooms (including a family restroom), cafe and visitor's center - note:  the hiking trails in park are not accessible per the ranger - $6/vehicle entrance fee to park ; additional fees for tours - (520) 586-2283 for tour reservations-  Big Room Tour is closed mid-April to mid-October (due to bat activity) - for more info go to http://azstateparks.com/Parks/KACA/access.html -  photo courtesy of Ellen from Arizona State Parks