— A cross-layer algorithm for geographic routing in Wireless Sensor Networks (WSNs) is proposed, which is robust to dead-ends and resilient to topological variations due to network dynamics. The solution combines ideas of network tessellation (clusterization) with greedy forwarding, without suffering from the problems afflicting landmark-based alternatives. The clusterization algorithm is based on a recently-discovered graph-spectral property and relies on connectivity information only. Cluster sizes can be varied, allowing for different trade-offs between Packet Delivery Success Ratio (PDSR) and Average Packet Delivery Latency (APDL) to be reached. Simulation results show that the technique can substantially improve the PDSR in networks where large concave holes (dead-ends) are present, with no or little impact on APDL.