Imagine you are standing in front of a forest, with lined-up trees. Each row and column is occupied by some infinitely thin trees. We consider each tree as a point. Behind visible trees, there must exist some trees that are blocked by these visible trees. The poster topic is about finding squares that contain all the invisible trees. By using the Chinese Remainder Theorem algorithm, the coordinates of the invisible squares can be found. Given standing at the point of origin, there exists an invisible square. First, by adjusting the location of the observer along x-axis and y-axis, the original invisible square’s movement is based on the path of the observer. Second, a common invisible square to three points was found. One further step could be finding the closest square to the origin. In addition, future study can focus on finding the common invisible square to n points, where n is greater or equal to 3.