Premise: Newgrange may be the world's oldest solar observatory the whole edifice is aligned in such a way that during several days of the winter solstice, light from the sun floods the inner chamber for approximately 17 minutes, a spectacular effect (the guide on the tour attempts to give an idea of this effect by plunging the chamber into darkness and slowly bringing up the light).

Hypothesis: Newgrange is a solar observatory.
Relation: entailment