Complex sentence: However, after it was built the feared disease did not occur in the Netherlands anymore so it was never used for its original purpose, it now serves as the entrance of Naturalis, one of the largest natural history museums in the world.
Split into simpler sentences: However, after it was built the feared disease did not occur in the Netherlands anymore so it was never used for its original purpose. It now serves as the entrance of Naturalis, one of the largest natural history museums in the world.