Where is flower paradise and hall of origin in pokemon diamond?

The flower paradise is a route extension, like the turnback cave added after beating the E4. but you need the event destributed item, OAK%26#039;S LETTER., or AZURE FLUTE for arceus, take it to the spear pillar and play it to start a staircase to the heavents, grab yourself that god pokemon. neithger event has happened yet though.c++