Progress in the investigation of emergent ground states and novel excitations in condensed matter systems relies on the existence of materials that are well described by simple theoretical models. Spin ladder systems have attracted a lot of interest due to the rich physics behind their simple mathematical description. Here we propose to investigate on a new isotropic molecular 2D quantum Heisenberg spin ladder Cu$2$(pz)${3}$(4-pyridone)$_4$(ClO$_4$)$_4$ with muons. This compound is unique in that it has comparable rung and leg exchange interaction strengths, allowing us to investigate a new regime of ladder behaviour.