In contrast to their 2D counterparts, three-dimensional (3D) PhCs are capable of providing complete photonic bandgaps (PBGs) in all three directions. Among them, the layer-by-layer (or namely the woodpile) PhCs have been intensively studied due to their flexible micro- or nanofabrication requirements and their robustness against fabrication imperfections34, 35. Such a structure consists of layers of parallel rods or logs, where the rods in each consecutive layer are rotated by 90°. Additionally, each layer with the same orientation of rods is shifted relative to each other by a half of the in-plane period (a), forming a 3D PhC of the symmetry of a face-centered tetragonal lattice. In this study, we propose a woodpile PhC with gradually varied longitudinal periods in the stacking direction, to gradually slow down and stop the incident wave. We first present the local dispersion analysis of such a configuration which suggest the choice of structural parameters. We then evaluate the intensity enhancement factors and calculate the spatial positions where the wave stops and the maximal field enhancement occurs, by means of instantaneous and steady-state field distribution analysis. Finally we verify the principle experimentally in the microwave regime, by comparing the numerically calculated and experimentally measured field profiles and the intensity enhancement factors.