What age is an adults only resort? Typically, you'll find the minimum age requirement for guests at an adults-only resort to be 18 and over. Some resorts do consider guests between to be adults, so it's best to check with each resort /5. Dec 13, · Located in the scenic Red Rocks of Sedona, Mii Amo is an adults-only resort with a world-class spa and countless wellness experiences for an unforgettable stay. Guests can Occupation: Associate Digital Editor.