  Multi-quanta, or giant, vortices (GVs) are known to appear in very small
superconductors near the superconducting transition due to strong confinement
of magnetic flux. Here we present evidence for a new, pinning-related,
mechanism for the formation of GVs. Using Bitter decoration to visualise
vortices in small Nb disks, we show that confinement in combination with strong
disorder causes individual vortices to merge into clusters or even GVs well
below Tc and Hc2, in contrast to well-defined shells of individual vortices
found in the absence of pinning.
