Skyscraper Sightlines Unblocked

Skyscraper Sightlines turns a grid into a little skyline. Each square holds one tower, every row and column uses each height exactly once, and every number on the outside says how many rooftops are visible from that spot. Taller buildings block the view of shorter ones, so the clues reveal far more than they first seem to. This is Simon Tatham’s Towers puzzle drawn in a neat 3D style, and you can play it unblocked here. Every generated board has a single solution reachable by pure logic.

How the City Is Built

Take a 5x5 board. Towers come in heights one through five, and each row and each column contains all five exactly once, just like a Latin square.

Now add the view. Picture yourself at a clue, peering down that line of squares. They see the first tower, then every later tower that is taller than all the towers before it. A shorter tower behind a taller one stays hidden.

For example, the row 3, 1, 5, 2, 4 shows two towers from the left (the 3 and the 5) and two from the right (the 4 and the 5).

Choose a square and enter a number to raise a tower. When you are unsure, pencil in the heights still possible and delete each one once it is disproved. Duplicate heights and impossible clues turn red, and the city flashes once every tower is correct.

Skyscraper Sightlines controls

To do this	Keyboard	Mouse	Touch
Build a tower	Pick a square with the arrows and type the height	Click a square and type a digit	Tap a square, then tap a digit button
Toggle a pencil mark	Press Enter for pencil mode, then type a digit	Right-click a square, then type a digit	Set Tap to Pencil mark or press and hold, then tap a digit
Empty a square	Space, Backspace or 0	—	Tap the square, then Clear
Pencil every possible height everywhere	M	—	—
Dim a clue you are done with	—	Click the clue	Tap the clue
New puzzle, undo, redo	N, U, R	Buttons above the grid	Buttons above the grid

Clue Tricks That Speed You Up

Some clue values are worth memorising because they solve squares instantly.

• The 1 clue. The square beside it holds the maximum height. Always.
• The full clue. A clue matching the board’s width, like 5 on a 5x5 board, means the line climbs 1, 2, 3, 4, 5 from that side. The whole line is done.
• The 2 clue. The tallest tower can’t be right next to it, or you’d see only one building.
• A general rule. With a clue of c on a board of size N, the nearest tower is no taller than N + 1 - c.
• Opposite pairs. A 1 on one side and a 2 on the other often pins the second-tallest tower too.

On bigger boards, the M key pencils every candidate into every blank square in one go. Trim them as lines fill up. Tapping finished clues to grey them out keeps your eyes on the clues still in play.

Levels, Sizes and Where to Go Next

The Type menu covers grids from 4x4 to 6x6 at four difficulty settings, the hardest being Unreasonable, and Custom stretches to 9x9. A portrait layout and a digit bar under the grid make phones comfortable, and the 2D option suits small screens.

If this kind of number placement clicks for you, Sudoku Flow is the natural partner, and Greater Than Grid adds inequality signs to a similar Latin-square idea.