There are a couple of ways to do that. However, if you want to avoid tracking variables, you could use the hasVisited() function. The code would be as simple as:
<<if hasVisited("Passage 1", "Passage 2", "Passage 3", "Passage 4", "Passage 5", "Passage 6")>>
[[Final passage|Passage 7]]
<</if>>
Now that final link to "Passage 7" will only appear if the player has already visited "Passage 1" through "Passage 6" (feel free to substitute your own passage names above).
Hope that helps! :-)