New continent grown by corals
In XX century, some artificial islands were built by UAE, Japan and China, but their land reclamation technologies were rather old-fashioned: large amounts of rocks, cement or clay had to be moved to a targeted area. That's why those artificial islands were small and very expensive to build. Now, with genetically modified fast-growing corals, one can easily grow a new island with pre-designed properties. This biotech method is even used to grow a whole new continent in Pacific Ocean.