This shape is very obviously visible.

It is in the quarry.

It is formed by the rails and ties near the water.

The shape is formed only by the rails and ties.

Stand on the quarry lift from the top position. Start the lift so it lowers, and as it does, start drawing the shape on the rails. Continue drawing as the lift lowers.

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This shape must be drawn as a single solid colour.

There is nothing you can do with the rails themselves.

You must have the right perspective to draw this shape.

Your perspective cannot be static.

How can we solve the two previous hints?

You cannot move while drawing lines.

Mechanisms take time to move.

You must use the quarry lift.