Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column and 3x3-box has exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point. The digits in marked cages have always a sum that is a multiple of 7 (i. e. 7, 14, 21, 28, 35 or 42). In cages there can't be the same digit repeated.

Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column and 3x3-box has exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point. The digits in marked cages are the last digit of the sum of the digits in the cage. In cages there can't be the same digit repeated.

Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column and 3x3-box has exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point. The coloured points tell you whether the sums in the marked cages are odd (yellow point) or even (green point). In cages there can't be the same digit repeated.

Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column and 3x3-box has exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point. The sums of the digits within each sub-region are equal to each other. In sub-regions there can't be the same digit repeated.

Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column and 3x3-box will have exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point.

In each 3x3 box their is a different rule to follow:

• Upper left - Even/Odd Sudoku: Yellow cells must contain odd digits, green cells must contain even digits.
• Upper centre - Min Max Quad Sudoku: The red points in the near of crosses where four cells meet each other show that the cell with the red points is greater then the three other ones. The blue rings in the near of crosses where four cells meet each other show that the cell with the blue ring is smaller then the three other ones.
• Upper right - Arrow Sudoku: The digit in the circle is the sum of the digits which are marked with its arrow.
• Centre left - Difference Sudoku: The numbers between two cells give the difference of the digits.
• Centre - Navigator Sudoku: The arrows show the location of the same number in the previous or next column or row. So for example, the arrow in fifth column means that the same digit is in the sixth column in row 6 - 9.
• Centre right - Greater/Less Sudoku: The inequality between each pair of digits must stand correct.
  

Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column, 3x3-box and cells of the same color have exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point. There are no neighbouring cells with a difference of 3.

Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column and 3x3-box has exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point. The digit in a circle is the sum of the digits which are marked with its arrow.

Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column and 3x3-box has exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point. All occurrences of each shape outlined in black (rotated and/or mirrored) must contain the same set of digits (possibly in different orders). None shape contains a repeated digit.

Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column and 3x3-box will have exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point. The arrows show the location of the same number in the previous or next column or row. So for example, the arrow next to the 2 in the first column means that the 2 in the second column is in row 6 - 9.
There is only one solution. You can find it by logic.

Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column and 3x3-box has exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point.