Unlike many of these other civilizations, the Greek civilization did not develop in a river valley, but it was bordered by water. Ancient Greece had the Mediterranean Sea to the south, the Ionian Sea to the west, and the Aegean Sea to the east. Greece is actually a series of islands—pieces of land surrounded completely by water—and peninsulas or pieces of land surrounded on three sides by water. These islands and peninsulas were covered with high mountains, making travel across the land very difficult. As a result, the ancient Greek people mostly traveled by water. Because Greece's mountains, islands, and peninsulas separated the Greek people from each other and made communication difficult, Greek civilization developed into independent city-states or cities that governed themselves and the land that surrounded them. Summary: