Pokémon Diamond and Pearl/Flower Paradise

Flower Paradise is home to the Legendary Pokémon Shaymin. As of now, the only way to get Shaymin and access to Flower Paradise is to either cheat with an action replay or trade with someone who has done so. He Flower Paradise is only accessible (with walk through walls) through Route 224, the route in Victory Road that opens up once you have defeated the Elite Four.

At the end of Route 224 there is a small gap between the water and another strip of land. Using walk through walls, walk across the water until you are on land a few steps away. Then hop on your bike and cruise through about two minutes of flowers. At the end on a stump of ground is the Legendary Pokémon Shaymin.