you open the door and enter :P it is this simple :P
Best Answer:To Get In Ruins Of Alph Battle The Guard On Left Side
Murkrow is found in the Lost Tower, at night, and only in Pokemon Diamond.
The Battle Tower
the lost tower
in fight area
Route 209
battle tower
top of the tower in solocean
you get him someow in the lost tower
in the battle tower
There is no Battle Frontier in Pokemon Diamond and Pearl. Only the Battle Tower.
At the fight area (after you beat the Pokemon league)
The Pokemon you see do not go in your pokedex.