1. India: Alexander's conquest of the Achaemenid Empire brought him to the border of India, but he did not venture further east. It is possible that he would have eventually invaded India, which was a wealthy and powerful region at the time.
2. China: China was another powerful civilization during Alexander's time, but it was far removed from his empire. However, it is possible that he would have sought to conquer China if he had been aware of its wealth and resources.
3. Egypt: Egypt was a powerful kingdom that coexisted with Alexander's empire, and it is possible that he would have eventually invaded Egypt if he had not died at a young age. Egypt was not conquered by Alexander III, but it would be conquered later by his general, Ptolemy I Soter.