The project of the major museum generates the contemporary new building. The old building and the new building have subtle conversation which one is on the ground and the other is underground. Under the relationship, the concept of the museum in woods becomes the connected bridge. Taipei Fine Arts Museum owns a vast grassland behind South Door. It is also the traffic intersection but lack of auxiliary space. Therefore, the project of the major museum solved the problem and the reversal of the relationship between South and North brings us a new imagination of the museum. The contention between artificial and natural has never stopped, and Postnature means to discuss the balance between artificial and natural to us. Nature fights back through the extreme weather, however, they could be no conflict if we create the ecosystem of the museum by the concept of landscape architecture and micro-detention to improve the relationship between artificial and natural. How to remodel South Door under the project of the major museum? Museum III is our challenge and our chance.