Complex sentence: He eventually found it in the ruins of the Diocletian's Palace at Split, Croatia; he observed that the palace had not weathered over the years, which Allward took as evidence of the stone's durability.
Split into simpler sentences: He eventually found it in the ruins of the Diocletian's Palace at Split, Croatia. Allward observed that the palace had not weathered over the years, a fact that Allward took as evidence of the stone's durability.