Wireless Sensor Networks (WSN) are receiving growing attention in the research community. As simulation is a frequently used approach to test and validate approaches, simulation environments need to be able to support the various WSN design schemes. Though the research trend in WSN is to address regions instead of single sensor nodes, existing WSN simulation environments still do not support modeling and design on this abstraction level. In this context, we propose MAP++ as a framework that extends the OMNeT++ network simulator. It provides a suite of tools needed to support WSN simulations. In particular, MAP++ supports map-based topology and scenario generation and evaluation. It also provides trace data visualization and database powered analysis. The usability of MAP++ is illustrated via examples of applications over each phase of simulation development, that is, modeling, design, implementation and performance evaluation. A case study for a map construction algorithm shows the utility of our tool chain to enhance common statistic-based trace analysis.