All four Gospels identify the place where Jesus was executed as Golgotha, meaning "the place of the skull" (Matthew 27:33; Mark 15:22; Luke 23:33; John 19:17). However, we don't know exactly where Golgotha was.
Where was Jesus crucified?
We do know it was near, or outside of, Jerusalem, as John 19:20 tells us and that it probably was on a hill or up high, as Mark 15:40 says it could be seen from a distance. We also know it wasn't in an out-of-the-way place as Mark 15:29 and Matthew 27:39 say passers-by remarked about the event.
To go to Jerusalem and find the location is difficult because Jerusalem has changed so very much during the past 2,000 years. In AD 70 it was destroyed by the Romans. Other battles have taken place and different groups of people with varying interest in identifying the location of Jesus' death have held control.
Two current sites lay claim to the historical location. First, the Church of the Holy Sepulchre has claimed the traditional site for 1,600 years. However, it is currently inside the city walls—but was it 2,000 years ago? The other nominee is Gordon's Calvary, identified about 150 years ago. Did its structure exist 2,000 years ago, or was it caused by quarrying since then?
No one really knows. As you may expect, there have been books and articles written about it. Here are some helpful articles for research:
Does it really matter? Not really. The exact location, if it is ever identified, holds historical, but not spiritual significance. What is significant is what happened there and nearby: Jesus died, was buried, then rose again to life defeating death, and more (1 Corinthians 15:3–4).
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Is the death of Jesus Christ or His resurrection more important?
Truth about Jesus Christ