The Castle Ruins That Defy ExpectationsStanding at the base of a crumbling stone tower changes how you think about Missouri entirely. The castle ruins alone are worth the trip, but the park has so much more waiting beyond that first breathtaking view. The Spring Trail is one of the most popular routes in the park and for good reason. Popular routes include the Spring Trail, Castle and Quarry Loop Trail, and the Dell Rim Trail. The aquatic side of the park tends to get less attention than the castle ruins and the trails.