Calvin Yang, reporting for the New York Times:
Building underground is not new in Singapore. About 12 kilometers, or eight miles, of expressways and about 80 kilometers of transit lines are below ground. Drainage systems and utility tunnels are common features beneath the urban landscape.
Now Singapore is going further, beginning work on a huge underground oil bunker called Jurong Rock Caverns. When this is completed, it will free about 150 acres of land, an area equivalent to six petrochemical plants.
Another project on the drawing board is the Underground Science City, with 40 interconnected caverns for data centers and research and development labs that would support the biomedical and life sciences industries. The science center, with an estimated 50 acres to be 30 stories below a science park in western Singapore, would house as many as 4,200 scientists and researchers.