The building spree is costing the impoverished nation more than $150 million, The Daily Telegraph reported Saturday, citing satellite photos and South Korean intelligence assessments. Kim Jong-un last month was named successor to his ill father, Kim Jong-il.
A house in central Pyongyang where Kim Jong-un grew up has been upgraded to luxury specifications. It is connected by a tunnel to his father's house.
A new villa in North Hamgyong province, known for its hot springs and spas, also is believed to be for Kim Jong-un. Local residents were forced to build a railway line and road leading to it, the report said.
A huge structure being built on the coast at Songdowon has an undersea gallery with a view of aquatic life 300 feet under the surface.
South Korean intelligence says the Kim family has at least 33 villas served by their own private train stations.
In November, the U.N.'s World Food Program said a third of North Korean children were chronically malnourished, along with many pregnant and nursing women.