Provided is a method for developing land through the workings of nature. An island (1) is covered with a sealing dome (3) larger than an aboveground part (1a) of the island such that a space (s1) is created between the island (1) and the sealing dome (3) and a lower edge (3a) of the sealing dome (3) is located in the sea, i.e., below the sea level (2). Subsequently, with a gap (s2) between the lower edge (3a) of the sealing dome (3) and a sea bottom (1b), a pile (4) secured to the lower edge (3a) of the sealing dome (3) with a bolt (not shown) is driven into the sea bottom (1b) to secure the sealing dome (3). Then, a pump (5) provided in the sealing dome (3) is actuated to reduce the air pressure of the sealing dome (3). According to the Pascals law, this causes the seawater to be drawn into the sealing dome (3), allowing the sea level (2a) inside the sealing dome (3) to rise above the aboveground part (1a) of the island (1). With the island (1) left under this condition, coral (6) will naturally grow thereon.
