Play Skyscrapers (Towers) online Works — plays right here, unlimited puzzles
Guide updated October 2026 · Runs via WebAssembly (native port)
Skyscrapers is a Latin-square puzzle shown as a city of towers: each row and column has one tower of every height, and the numbers round the edge say how many towers you would see looking in from that side, with tall towers hiding shorter ones behind them. The puzzle is ready below; click a square and type a height.
Controls — what does what
| Action | Keyboard | Mouse / touch |
|---|---|---|
| Select a square | Arrow keys | Left-click |
| Build a tower | Type its height | Click, then type |
| Pencil marks | Enter toggles pencil mode, then type | Right-click, then type |
| Clear a square | Space | Click, then Space |
| Fill all pencil marks | M | — |
| Grey out a used clue | Ctrl or Shift + arrow | Left-click the clue |
| Undo / redo | U / R (or Ctrl+Z / Ctrl+R) | Game menu buttons |
FREE This is the complete game, free. Open source under the MIT licence: the complete puzzle, with a new grid every time.
Towers is from Simon Tatham's Portable Puzzle Collection, © Simon Tatham and contributors, used under the MIT licence. Built from source by scripts/build-puzzles.mjs.
How to play
On an N×N grid, build a tower in each square with a height from 1 to N so that:
- each height appears once in every row and once in every column;
- each edge clue equals the number of towers visible from that point, looking along the row or column; a tower is hidden if any taller tower stands in front of it.
So a clue of N means the heights rise steadily away from it, and a clue of 1 means the tallest tower is right next to it. In larger or harder puzzles some towers are placed for you and some edge clues are missing.
Sizes and difficulty
Presets cover 4×4 Easy, 5×5 Easy and Hard, and 6×6 at Easy, Hard, Extreme and Unreasonable. Unreasonable needs some trial and error; the other levels can be reasoned out. Custom goes from 3×3 up to 9×9. If you find the 3D drawing hard to read, Preferences can switch to a flat 2D view with plain numbers.
Solving tips
Place the certainties first: a clue of 1 puts the tallest tower beside it, and a clue of N fixes the whole line in rising order. A tower of height N can never be closer to a clue than (clue − 1) squares away, so a clue of 3 keeps the tallest tower out of the first two squares. Opposite clues that add up to N+1 often pin the tallest tower's position exactly.
Where this puzzle comes from
Towers is part of Simon Tatham's Portable Puzzle Collection, a set of about forty logic puzzles written by Simon Tatham and contributors and released under the MIT licence. Every grid is generated on the spot, so the supply never runs out, and for the grid-logic puzzles the generator makes sure each has exactly one solution, reachable by reasoning rather than guessing. The version here is the collection's own code compiled to WebAssembly; the Game menu can save a puzzle to a file and load it again, and the Type menu changes the size and difficulty.
Frequently asked questions
Do I have to count the tower right next to the clue?
Yes. The nearest tower is always visible, so every clue is at least 1.
Is there one correct answer?
Yes. Every difficulty level, including Unreasonable, is generated with a single solution.
Is Skyscrapers free to play here?
Yes, with no limit on the number of puzzles. Towers is open-source software under the MIT licence, and every grid is generated fresh when you press New game.
Does it work on a phone or tablet?
Yes. A tap works as a click and the puzzle resizes to fit the screen. Puzzles whose controls use the right mouse button are easier with a mouse.
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Want a game like this on your own site?
Skyscrapers (Towers) isn't ours to give away — we host it, we didn't write it. But eleven of the games here we did write from scratch, and those are free for anyone to put on their own page: one line of HTML, no account, no permission, no attribution beyond a credit line.