Differential erosion in karst topography of Belize forms closed basins around karst towers. Ephemeral lakes that collect in the basins are active in removing talus and undermining hillslope support by corrosion. Channel incision establishes more rapid drainage of the basins that surround towers, resulting in less active hillslope erosion. Tower karst topography of coastal Belize is in the process of changing from a landscape characterized by rapid talus removal and undermining to a landscape characterized by slow talus removal and little slope undermining. As the drainage continues to improve around karst towers, steep tower hillslopes become more obscured at their bases by the accumulation of talus.