Examples:

• The old pirate map had an X marking the spot where the treasure was buried.
• We searched the entire forest, but couldn't find the lost hikers until a helicopter spotted them and X marked the spot for the rescue team.
• The detective followed the clues to the abandoned warehouse, where he knew X marked the spot of the criminal's hideout.
• After days of searching, the archeologists finally found the ancient ruins, marked by an X on the map they had been studying.
• The treasure hunters dug deep into the sand, hoping that X marks the spot where the long-lost shipwreck had sunk.
• The children played a game of hide and seek, and one of them shouted "X marks the spot!" to signal that they had found the best hiding spot.
• The construction crew was told to excavate the area where X marked the spot for the new building's foundation.
• The rock climbers looked for the route that would lead them to the summit, where they knew X marks the spot for the best view of the valley.
• The fishermen followed the GPS coordinates to the exact spot where X marks the spot for the best catch of the day.
• The artist made a mark on the canvas, where X marks the spot for the focal point of the painting.
• Well, as we say in the business, X marks the spot.
• But look: X marks the spot.
• Because X marks the spot.
• X marks the spot of the buried treasure.