We are given several sets of directions. The first set of directions mentions a “central station”, “McDonalds” and “Starbucks”, but unfortunately this is insufficient to narrow down the search space meaningfully. Scanning the rest of the instructions we see a reference to “Delft”, which suggests that we might be in the Netherlands. This combined with the preponderance of bridge crossings mentioned leads us to realise that we are actually in Amsterdam.
Starting from Amsterdam Centraal, we follow the first set of instructions to end at the De Drie Fleschjes cafe located at Gravenstraat 18. However, we are not so lucky with the rest of the instructions, some of them don’t even have clearly defined end points.
The last paragraph gives us a hint on what to do. After conducting some research on airlines and souvenirs, we realise that the Dutch airline KLM regularly gives out miniature models of houses to passengers on their planes as souvenirs. Each of these miniature houses are based on actual buildings in Dutch cities including Amsterdam. With this information we realise the destinations of each of the sets of instruction is a KLM house which we can extract from. Instructions with an unclear end point are ones where it needs to be constrained via the list of KLM house locations. The 5 traits mentioned in the rest of the last paragraph provides the final extraction step - we can simply convert the true/false values for each house to a single letter via 5-bit binary to get the answer GOLFLENGTE (translation: wavelength).
Address | KLM House ID | G at least 15 blue blobs on front | Has stairs going up | They have alcohol[1] | ID is 60 or later | More than 2 side blobs | Bits in binary | Binary to letter |
---|---|---|---|---|---|---|---|---|
Gravenstraat 18 | #80 | 0 | 0 | 1 | 1 | 1 | 7 | G |
Prinsengracht 305 | #62 | 0 | 1 | 1 | 1 | 1 | 15 | O |
Herengracht 101 | #58 | 0 | 1 | 1 | 0 | 0 | 12 | L |
Keizersgracht 403 | #66 | 0 | 0 | 1 | 1 | 0 | 6 | F |
Keizersgracht 104 | #40 | 0 | 1 | 1 | 0 | 0 | 12 | L |
Prinsengracht 773 | #54 | 0 | 0 | 1 | 0 | 1 | 5 | E |
Prinsengracht 969 | #68 | 0 | 1 | 1 | 1 | 0 | 14 | N |
Keizersgracht 755 | #64 | 0 | 0 | 1 | 1 | 1 | 7 | G |
Prinsengracht 514 | #42 | 1 | 0 | 1 | 0 | 0 | 20 | T |
Herengracht 415 | #52 | 0 | 0 | 1 | 0 | 1 | 5 | E |
Here is an annotated version of the walking tour.
After exiting the central station from the main entrance, begin walking southwest. Soon, you will reach a point with a McDonalds to your right and a canal view on your left. Continue along the same street until you reach a Starbucks. Turn right into the immediate next alleyway and walk along it. Cross the next intersection into another alley street. Continue until seeing a sign with a bigram above a bright red door. Past that sign is a cafe/bar, which is your first destination.
You continue in the direction you were walking in before. You walk around the church and admire its front entrance – strange that they call it a new church when it was made in the 15th century. You walk past the palace (it’s so grand!) before immediately turning right. Travelling against the flow of traffic, you cross water three times – as you do so, you pass by some truly Extraordinary Gifts as well as Gamekeeper. Enviously, you stare at the watches in the window to your left. Instead of crossing water for a fourth time, you make a right immediately. You reach your second destination.
Continue walking along the road, keeping the water on your left side, until you pass by a breakfast place next to a tours shop. Take a right turn around the breakfast place, then a left when you cannot walk forward any more. Continue in that direction until you see a red hat.[2]
Then turn right, crossing over the water and turning right immediately after. You'll pass a bust of Comenius in front of a diplomatic office of sorts, and should then turn left at a corner with a small cafe. Continue until you see a fast food place. From here, you turn left again, following the water. There should be a small inlaid carving along a building on our right.
You continue crossing the street past this building. Your destination is the 3rd building on our right after the intersection.
Walk to the nearest intersection,[3] then start crossing bridges in the northwest direction. After crossing 3 bridges, you turn left and walk parallel to the canal. You laugh when you see some silly police stopping a bus. You’ll soon reach a museum dedicated to a certain type of flower. Turn left onto the very next bridge, cross it, and then walk along a familiar street.
Walk left after crossing two bridges. As you pass a shop you might have forgotten (did you realize you were here before?), turn into an alleyway filled with greenery. As you exit, turn towards a coveted garage space. You pass by a bust of a satirical novelist. Keep going straight, passing the Number 1.
Turn at the warning sign. At the other end, oppose the flow of traffic. Keep going past the soldier in blue. When you see the cheese shop, cross the bridge and traverse on the other side, now following the flow of traffic. You learn about all the canals around and keep going.
Avoid bridges for the rest of this leg. Across the water, you spot an art gallery. You keep going and arrive at your destination: a white building that’s adjacent to one with a French name.
Continuing ahead, you pass by a gated courtyard to your right. Keep going past a window with a word printed five times with various amounts of blue. Turn right at the square yellow-orange sign. Passing through, you see beauty shop and an art gallery. When you meet the water, turn towards the adjacent houses painted black. Continue along the path.
Looking into a corridor, you walk towards a backwards N. Turn right after the displays of mannequins at the corner. Take the next left after that. You see a large church in front of you and cross from one large triangle on the sidewalk to another. Looking around, you see people lined up for a museum. You ask what it is for and hear the story of someone who died. Pass by them and turn right.
Cross the bridge at the intersections with some movie posters on the corner. At the T-junction on the other side, you catch a whiff of something cheesy close by. Follow your nose, learn how to make cheese at this location, and keep going past. At one point, you look up behind you and laugh again at the silly police. Take the next right. You pass a sign that almost sounds like a planet, and then another with a pair of dancers on a sun. After passing a sign of a mouth licking their lips, make a right. Your destination is the building after one with large letters.
Going southwest, you look towards your left where you see where you freed your mind earlier. You take the next right until you can go straight no longer. You could learn about how plants affected the economy to your right, but you take a left instead. You go straight. Keeping left, you pass a canal and a street named after flora. You pass an odd shop that features numerous Funkopops. You continue on your way and are spooked by the masks that adorn a store. You go over a bridge. You continue a couple of blocks when you pass by a museum on the water on the left – you didn’t know there were things to do there. You then walk past a bunch of dolls to your right. Going straight, you pass by a second life shop. You cross water. After picking up a burger, you immediately turn left and immediately turn right. Now walking with the water on your right, you cross the tracks. Your next destination is after the red and white stripes.
Continuing in the same direction, you take the first right. You pass by a cafe named after a famous fairy tale. You cross two bridges. If you were a normal tourist, you’d continue straight and enter the largest museum of the city, but because you’re a puzzle hunter, you turn left. You continue down the street where you find the brewery for a famous beer brand – you turn left when you see it. You enter a traffic circle, and, if you were driving, you would’ve taken the second exit. You cross two more bridges and then immediately take a right at the bagel shop. Going a little further, you get to your next destination… Hey, why did you make such a detour?? You could’ve just walked straight from our last destination.
Walk west and turn right immediately at the next intersection. You will see a giant pair of spectacled eyes in a window at an intersection. Turn right here and walk alongside the canal, crossing some bridges until you reach the river the city is named for. Cross the bridge to the left, turn left again, and continue walking. Your destination is the building with a lamp in front of an arched door.
Walk with the water on the right, until you hit the end of the road, then turn right. As you keep walking, you should spot a thin bridge on your left. Do not take the bridge - instead keep going straight until you cross a similarly thin but less well-known bridge. Continue straight until you spot a building with greenery all along the building face.
Turn right at this building, walking by a park. Continue walking along the border of the park until you see a little slice of Spain. Turn right such that it's on your left, going to the end of the road, then turn right. Turn left at the corner of a travel agency advertising "Perfect Travel".
From here, it is a straight journey with no more turns. After walking by a bridge, you should pass five open white "doors" on your left – they're stacked vertically. Your destination is about midway between the previous bridge and the next one, with a Ford logo on the building wall.
It’s almost the end of the day, and you continue walking with the canal on your left side. A colorful rhino on your right catches your eye. Next, you cross the bridge on the left. Since it’s almost the end of your trip, you splurge on souvenirs on the next block – you buy a Delft version of every building[4] you’ve passed by from the corner store, then a few antique vases from the multiple nearby options, and some gold. Taking the next left, you pass a bike rental repair shop. As you approach the end of the block, you admire the rainbow typography on your left. You turn right once you reach the tracks. You can’t stop yourself from buying a round of cheese from the store on the left; they were just stacked so appealingly. You continue down the street, passing by the bus stop as well as various fashion stores. You buy even more cheese, as this store is named after the city you’re in, so it must be good. You cross the bridge and take the left. You finally get to your last destination.
Tracey: We didn’t notice that our answer had a 1 for the 3rd bit for every letter until after we finished constructing the puzzle! We changed the definition of the 3rd bit from whether the identifier was even to whether the KLM house had alcohol since that’s cuter… but it did mean we killed half of our data for no reason oops.
Alex: I did a dictionary search out of curiosity and the odds of a random 10-long answer having this property was about 1 in 500. Very spooky.