Many Moons (and Suns) Ago

Question

_{This is part 12 of the puzzle series Around the World in Many Days. Each part is solvable on its own.}

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Many moons ago, on an island far, far away…

Deаr Puzzling,

Today I have a Moon-or-Sun puzzle for you. The grid is divided into rooms. Draw one continuous loop which visits every room exactly once, going horizontally or vertically through centres of cells without crossing itself or branching out. The circles in the grid represent moons (black circles) and suns (white circles). In every room, the loop either passes through all the suns in the room but none of the moons, or all the moons in the room but none of the suns. “Moon” and “sun” rooms alternate, so if the previously visited room was a “moon” room, the next room has to be a “sun” room and so forth.

In the crossword (light grey numbered cells), each answer is written around the numbered cell either clockwise or anticlockwise. Any of the cells surrounding the number can serve as the starting point.

Today I have explored bustling markets and beautiful sandy beaches on a picturesque island. Can you guess where I am?

Love, Gladys.

Crossword on Penpa+
Moon-or-Sun on Penpa+

1. The core personnel of a military unit
2. Evacuate from a fighter jet, say
3. Lighthearted
4. "Ugly" TV character
5. Reads a QR code, perhaps
6. A river's curve
7. People ready to depart on a moment's notice
8. Artistically stimulated
9. Afghanistan is their graveyard
10. A long look
11. Equipped with weapons
12. Advertises
13. Engine
14. Message received

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Gladys will return in Under the Surface.

Answer 1

The solved crossword is below:

Clue answers:

CADRE, EJECT, CAREFREE, BETTY, SCANS, MEANDER, STANDBYS, INSPIRED, EMPIRES, STARE, ARMED, MOTOR, ROGER.

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Moon or Sun logic:

To start, we don't need to worry about the moons or suns - instead, try to figure out the overall path that the loop takes through the rooms. The fact that each room is entered exactly once is important.

The 1×1 near the lower left has its two neighboring rooms already decided, as does the 1×2 room below it.


Now, the right endpoint can't go up to the room above it, or the two endpoints would need to join and complete the loop early. It must escape through the region on the right instead.


Meanwhile, in the upper left, we can't grab the sun without returning to the same room we just left from. So that must be a moon room...

...and if the moon room goes down to the region below it, the suns "pull" the line to the right. So that region does not connect that way.


Of course, this makes the region in row 4 a sun region anyway, and that lets us deduce the types of many of the rooms...

...which lets us draw actual segments of the loop now...
...and the rest of the puzzle resolves itself smoothly.

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To figure out Gladys' location,

simply read off the letters in the unused cells. These spell out DJERBA, a large island off the coast of Tunisia.