Viscoplastic fluids are encountered in a wide range of applications, from confined flows in industry to free surface flows in geophysics. For the latter, the flow is often influenced by topographical features that can block, redirect or channel the flux. Finely modelling the complex interactions between rheological effects and topography is of a great importance, e.g. in natural hazard management to predict flow trajectories and runout. If numerous experimental studies of viscoplastic surges down planar slopes or inclined channels can be found in the literature,experiments of viscoplastic surges on complex topographies remain rare. To that end, we report on well-controlled experiments aimed to characterize transient flows of Carbopol on 3D-printed model topographies. The fluid is released from a rectangular reservoir (column collapse). Using Moiré projection and Fourier Transform Profilometry, the evolution of flow thickness over time can be recovered with a typical accuracy of 0.5 mm and a temporal resolution of 250 Hz. Release position, release volume, fluid rheological properties and the topography itself are varied to investigate different flow regimes and interactions with the topographical features. In particular, an abrupt transition is highlighted between an initial inertial regime and a regime mainly controlled by rheological effects. The influence of obstacles (dams, mounds) on this transition is observed. Preliminary comparisons between these experimental results and numerical simulations relying on shallow-flow assumptions will also be shown, with the objective to assess the predictive capabilities of the models.