We summarize recent results on the volume dependence of the location of the critical endpoint in the QCD phase diagram. To this end, we employ a sophisticated combination of Lattice Yang--Mills theory and a (truncated) version of Dyson--Schwinger equations in Landau gauge for $2 + 1$ quark flavours. We study this system at small and intermediate volumes and determine the dependence of the location of the critical endpoint on the boundary conditions and the volume of a three-dimensional cube with edge length $L$. We also discuss recent results on baryon number fluctuations in this setup.