The Romans were experts at building with precision at significant locations: e.g. the Vatican Basilica in Rome originally built by Constantine with the high altar directly over the grave of Saint Peter, as it is today.
There is one much deeper reality which must be kept in mind as one visits the Holy Places and hears all the discussion about accuracy of place. Men fight about land and places and temples, but Christ declared that He Himself is the True Temple of God. Places are not Holy except from the Holy God who makes anything Holy that is Holy. Christ said "the Kingdom of heaven is within you"! Christ and Jesus Christ alone is God's Holy Temple, God's Holy Place, the Holy Land. You are in the Holy Land in so far as you are in Christ, living in Him and He in you. That, in fact, is heaven. Heaven is fundamentally a relationship. God is love. He who lives in love lives in God and God in Him.
You are truly in the Holy Land only when you are holy! And, if you are holy, you are in the Holy Land no matter where you are. The Holy Land is within you!, in your parish tabernacle, in your personal dedication to the daily duties of your state in life: your family, your work, your personal relationship with Christ. There are no territorial substitutes for the love that God has for you.