Vacuum

Vacuums, such as the vacuum of space, contain no matter of any type. Usually, one thinks of the vacuum as having no atmosphere, but there's also a lack of solids or liquids as well. The vacuum does however often contain photons. This doesn't stop it from being a vacuum, because photons do not contain matter. This is how the vacuum can still exist at some temperature above absolute zero: the photons allow it to have that thermal energy without having matter.