Left wanting more

Question

_{This is part 14 of the puzzle series that started at Living the traveller's dream. This is the final puzzle in the series and solving it requires knowing the answers to the previous puzzles.
Previous parts: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13}

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Dear Puzzling,

Hello from back home! I have had a wonderful time on my trip and visited tons of exotic places. However, every journey, no matter how extensive, still makes you choose between places you are going to visit and some places that you have to leave for another time. In this final puzzle, I would like to mention a few that I did not get to visit this time. These include a buzzing modern metropolis, an impressive yet approachable mountain top, a walled settlement overlooking a stunning valley, and an extreme point of the world at least when us humans are considered.

In the first twelve puzzles of this series, two thematic answers share a special relationship. You may figure this out just by looking at the solved grids; in case you have trouble figuring it out, the solved grid of the thirteenth puzzle contains two hidden words which reveal the nature of this relationship. In each of the grids 1–12, locate the two special answers and pick the letters that match their corresponding squares in the next puzzle in the series. These letters form a short keyword. Note down these twelve keywords and the number of the corresponding puzzle (1–12).

In 31 clues, one word has been translated into one of the four non-English languages I have needed during this trip. These must be translated back to English before solving. All translations can be found in the English Wiktionary, although not necessarily as the first definition listed in every case. If the translated word is the clue’s mth word, highlight the mth letter of the clue after translation. The highlighted letters spell out a list of destinations I did not get to visit this time around, but would like to come back to at some point in the future.

In the remaining 36 clues, one of the twelve "keywords" from above has been removed from the clue and must be restored before solving. (Each keyword is missing from exactly three clues.) If the missing word is the keyword from the nth puzzle, highlight the nth letter in the complete clue (including the keyword in its proper place). The highlighted letters spell out what to do with the finished grid to uncover a final description of my voyage, which is on the other hand kind of accurate but at the same time not accurate at all.

Thanks again for following my journey. Take care!
Love, Gladys.

Across
1. US president's height: Ultimately, one pie (4)
4. Restaurants empty after Ms Blanchett provides prepared in advance (6)
7. Clothes stripped from next to church's curved passageway (4)
11. "Vehicles' there mention potatoes, in retrospect", some gringo had indicated (5)
12. Famed Broadway production shown behind back seat (5)
13. Drops of Campari and Aperol and cola? Cocktail containing no Lima boon (5)
14. Extremely venerable premiers to immediately cover (4)
16. Employer's sure spelt out Anders (4)
17. Quiet politician captured Rhode Island mar creature (6)
18. Confession maker possibly struck close to the centre (5)
19. Quite adequate western walls in, basement, library etc. (4)
21. Decapitating hound makes, say, money in? (5)
23. A transportation method by for coach (5)
25. Get a load of perhaps (4)
26. One dwelling in rocky shelter around Valencia – at first surprisingly (8)
28. A sort of initially not able to describe character in fiction (7)
30. Extremes in Equestria trapped between walls of bubble (4)
32. In turn, US computer firm, to get in touch with half of AC/DC, by phone (6)
34. Page missing in novel describing fish eggs (4)
35. Literary alter ego to stay unseen for the assistance (4)
38. The referendum camp that lost 'em aboard line made north (6)
39. In sound, clings to Rio (4)
40. Keen attention ruined (7)
42. It is recalled after samba dancing: Something to comer (7)
44. Astute paid athlete turned to write incredible introductions in (4)
45. Groups for gripe vaccination? I attract generous backers (5)
48. Detached apartment's entrance, with bobo going the wrong way (5)
49. South African preacher's dance habit (4)
50. Texas's leading rock group's name, with a double punt atop a letter (5)
52. Deceptively clever tempo to move back – apartment leased further (6)
53. Uproar – single step of trap is scratched in the middle (4)
54. Expel forcibly from second rang in church (4)
55. Unusually creepy new I've regularly ignored (5)
56. Go back to position that occurred initially, returning erroneously collected (5)
57. Meet one's maker, or coated, for so long (5)
58. Satellite canal covering applied science (4)
59. Deity of ancient Egypt appearing in place of Liu (nearly guy), finally showing spirit (6)
60. UK city hospital chasing flying Zorro? (4)

Down
2. Arabian port monster made news (4)
3. Delicate to consciousness (5)
4. The king's entourage pretender a love interest? (5)
5. Egyptian lost thousand following article (6)
6. Drunk NY Rangers: "I lost backer in hockey and up" (5)
8. All save one Stack Exchange's salary increases (6)
9. Big US city sob lead of Hemingway, a writer making money (2'5)
10. This series's overall theme is sale, aromatic hues (5,7)
15. Links editor with chore: Finally creating opening paragraph (4)
18. Behind bars of Doctor Lance, citadel changed mains twice (12)
20. Shopkeeper does what being interrupted by quiet rust periods? (6
22. Shakespearean villain, among others, Mercutio at last (4)
24. European leader made it a captivating thing, essentially (7)
27. Mama to a colt, maybe from oddly area with no limits (4)
28. Misled by president's first scheme (4)
29. Beast of burden surface of novelty gemstone (4)
30. Cut hart of Matt Groening character who likes drinking Duff in The Simpsons, for example (4)
31. Miss Adams' once prisoners (6)
32. Frontliner of going north of Panama perhaps leads to discussion (4)
33. Has brunch, perhaps supplied by central figures of Scotsmen (4)
36. Drops stashed securely away after we escaped from the midi (4)
37. Ugly enveloping hurt carpenter's tool (4,3)
41. Altruistic Enzo Ferrari technician fins up receiving core part in turbines of metal (6)
42. Heartless US president holding couple in, being subjected to canine attack? (6)
43. Planet of bras? Man moved up (4)
45. Express orally: "Club to its tip" (5)
46. Like dier that's lost small plate (5)
47. Brown bonobos, maybe climbing, have got heart (5)
51. Gather animal parts as described in parole (4)

Answer 1

In the first twelve puzzles of this series, two thematic answers share a special relationship. You may figure this out just by looking at the solved grids; in case you have trouble figuring it out, the solved grid of the thirteenth puzzle contains two hidden words which reveal the nature of this relationship.

As the 13th grid shows, the nature of this relationship is ROTATIONAL SYMMETRY.

In each of the grids 1–12, locate the two special answers and pick the letters that match their corresponding squares in the next puzzle in the series. These letters form a short keyword. Note down these twelve keywords and the number of the corresponding puzzle (1–12).

Taking the rotationally symmetric entries, and looking at which letters in the next grid match up with those, we get the twelve keywords:


The keywords are: LOSE, PROSE, NETS, RAIL, EARL, CLAN, RANG, MEAN, BANK, ATTIC, PLATES, BLIND.

In 31 clues, one word has been translated into one of the four non-English languages I have needed during this trip. These must be translated back to English before solving. [...]

In the remaining 36 clues, one of the twelve "keywords" from above has been removed from the clue and must be restored before solving. [...]

And now it's time to solve the clues!

Filled Grid

Clue Explanations

The four languages spoken in the visited countries are Spanish, French, Portuguese, and Dutch. I've used colored brackets to mark those in the clues. (A few words had more than one language that worked; in those cases I just chose arbitrarily.)

The remaining clues are the 36 that required each of the twelve keywords to be added. Those are marked in black.

[...] If the translated word is the clue’s mth word, highlight the mth letter of the clue after translation. [...]

[...] If the missing word is the keyword from the nth puzzle, highlight the nth letter in the complete clue. [...]

These are in the above image, in between the clues and their corresponding answers.

Finale

[...] The highlighted letters spell out a list of destinations I did not get to visit this time around, but would like to come back to at some point in the future.

[...] The highlighted letters spell out what to do with the finished grid to uncover a final description of my voyage, which is on the other hand kind of accurate but at the same time not accurate at all.

The brown letters spell out four places Gladys wanted to visit but couldn't: SAO PAULO, CHACALTAYA, KUELAP, and USHUAIA.

The black letters spell SHADE OUT ALL SQUARES USED BY SPECIAL CLUES. The "special clues" are the ones mentioned in the instructions: the two rotationally symmetric clues related to Gladys' location from each of the first twelve puzzles.

This grid is 15×15, just like all the previous puzzles, so we can overlay all the previous grids on it. After shading out the corresponding squares, as instructed...



...we see that THIS TRIP REALLY WENT SOUTH, which is literally true because all the countries were South American, but colloquially implies a far worse trip than the pleasant vacation that Gladys described to us!