An additive manufacturing obstacle part can comprise a base structure comprising at least one external obstacle, and at least one internal obstacle that is formed at least partially within the base structure. The at least one internal obstacle can comprise an elongated internal obstacle extending through the base structure between an inlet and an outlet formed in the base structure. The elongated internal obstacle can comprise at least one wall extending along a nonlinear path. The non-linear path can hinder travel of excess material from an additive manufacturing process along a linear path between the inlet and outlet. This can help a designer to assess an additive manufacturers ability to cleanly produce an internal feature to specifications while removing excess material resulting from the additive manufacturing process.