  We reveal the center vortex content of SU(2) calorons and ensembles of them.
While one part of the vortex connects the constituent dyons of a single
caloron, another part is predominantly spatial and can be related to the twist
that exists in the caloron gauge field. The latter part depends strongly on the
caloron holonomy and degenerates to a plane between the dyons when the
asymptotic Polyakov loop is traceless. Correspondingly, the spatial vortex in
caloron ensembles is percolating in this case. This finding fits perfectly in
the confinement scenario of vortices and shows that calorons are suitable to
facilitate the vortex (de)confinement mechanism.
