You are facing the front of the castle and portcullis. To the right is the ramp where the railcar was before. To the front-right part is the river. At the back via right side is the water wheel.
After you crash the rail car to the scaffolding - then go to the scaffolding. You can always follow the rail track that the rail car rode on or just go to the left of the portcullis which is the gate at front of the castle.
If I'm reading the walkthrough correctly, to get to the iron curtain you go back of the balcony and right to the hanging walkway above the theatre. Cross the hanging walkway and go through the door to be down on stage at the main theatre level. Go left and see the iron curtain on the stage.
Looking at the walkthrough, it says that you find 3 of the vases around the pile of dirt from Adam's grave. You can also find another vase in the shed in the cemetery - maybe this is the fourth one that you need?
Am at the end of Haunted playing the bonus and cannot find that piece of plank. Have touched every plank in sight and still not able to pick up. According to walkthru it is on left of swamp but am having no luck. Thanks