We demonstrate the tunability of a GaAs/AlGaAs quantum ring showing coherent Aharonov-Bohm oscillations up to a gate voltage regime where the ring splits into three quantum dots. This is explained based on the structure's special confinement potential. We characterized the dots by analyzing the corresponding sets of Coulomb blockade lines. Additionally, the spatial configuration of the dots was confirmed by charge measurements using an adjacent quantum point contact. (c) 2008 American Institute of Physics.