The automatic generation of hardware implementations for a given algorithm is generally a difficult task, especially when data dependencies span across multiple iterations such as in iterative stencil loops (ISLs). In this paper, we introduce an automatic design flow to extract parallelism from an ISL algorithm and perform a design space exploration to identify its best FPGA hardware implementation, in terms of both area and throughput. Experimental results show that the proposed methodology generates hardware designs whose performance is comparable to the one of manually optimized solutions, and orders of magnitude higher than the implementations generated by commercial high-level synthesis tools.