Some summary first. A couple of weeks ago, a collaegue of mine had played with one of my custom magic puzzles, more specifically, the Secret of Atlantis. After seeing its structure, he suggested to make something more impressive, for example like the world trade center.

For me, that was a brilliant idea, because there was an extra motive to do so. Back in 2000, I was in Manhattan for a seminar and had visited the Twin Towers. It was a cloudy August day, but the way the clouds were covering both towers was a sight I could never forget. A year later, they were gone in a horrific way. I could not believe what had happened.

So decided to make a paper design and check if making this puzzle with a single closed loop was feasible. It definitely was! After making the Tower of Mahjong, I gained some valuable experience for making magics which looked like a tall building. The next step was to calculate accurate dimensions. The height to width ratio was a good 6:1, making each tower 6x4 (side tiles) + 1 (top tile) = 25. Both of them were 50 tiles, while the ground part needed exactly four tiles. Total of 54.

As you probably know, a magic puzzle has two sides (unless it is a... Mobius Magic!), and the world trade center was the solved state of one of the sides. I was wondering what the solved state of the other side should be. Then I remembered that a few months ago, I was considering making a 3x3x3 cubic magic maze.

But of course! A 3x3x3 cubic magic, ALSO needed 54 tiles.... BINGO!

This time I was not thinking of the maze theme, but of the 3x3x3 deluxe color theme. I deliberately made reaching the cubic state a difficult task, making the closed loop going around the cube in a similar (but not same) way with the one used in the Maze Cube.

So after doing more "research" to make sure both world trade center theme and 3x3x3 deluxe cube theme
are correct, and that the design has the appropriate papers tiles, I present you the "Memory Cube". I gave it this name, because one solution is cubic, while the other solution is the world trade center the way I want to remember it, the way it stayed in my memory when I visited Manhattan back in 2000.

Note that the world trade center looked different from different angles and it offered a different panorama during many times of the day. In this puzzle, depending on the angle, it can have the morning look, the midday look, the evening look, and the night look. I made sure I put some effort on the detail, as I wanted this puzzle to be perfect. The visible window images and the offset placement was *very* intentional. I spent a lot of time to make sure I get the details, architecture, and the dimensions of the entire place correctly. Also, I had to places some cartons (internally) to make the towers and the cube states more stable, as well as some rubber bands!

Each side of the cube state has a side of 16.5cm (6.5 ''), while for the wtc state, I placed my small screwdriver on the top of tower 1, to make it look more like the real thing!

Generally speaking, this puzzle took me a while to make, including the design, the correct placement of all the 108(!) paper tiles, as well as the tedious stringing of 54 tiles. I did many mistakes on the way, which I corrected, but was delayed considerably. I love each of the solved states for different reasons. But blending those two solved states together into one puzzle, is something that I don't think I will be able to top in the future. When I realised that not only *both* states needed exactly 54 tiles, but that their structure also made it possible to going from one solved state to the other, I knew I was sort of lucky too! :-)

I leave you with plenty of photos: