The lands where Abram lived is the land of Canaan, called Israel today. That, then, is the Promised Land - and that is why it is called the Promised Land.
But for how long? Forever! The inheritance is to be an eternal inheritance, which of necessity involves and includes everlasting life.
If one inherits a piece of land, the deed must describe the exact boundaries of the property. Is such a description given in this deed of the land we may hope to inherit? The answer is found in Genesis 15:18, "In the same day the LORD made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates." From the Nile River in Egypt to the Euphrates in the Near East!
We have all seen enough maps to know where that is, and I am sure we all know it is not up in heaven somewhere, but right here on this earth. "And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise" (Galatians 3:29); and the promise - the promise of eternal inheritance - is the land of Israel, from the Nile clear to the Euphrates, here on this earth! God help us to put our trust in the sure Word of God, not in the fables of men!
Other scriptures show that the territory of Christ's Kingdom is to expand and spread until ultimately it shall include the whole earth. See Romans 4:13.