Musk also hinted that the Boring Company was willing to create underwater tunnels, although there haven't been any announced so far.

The entrepreneur didn't explain just why the company was expanding to China, although there are a few potential reasons. For one, it might face less opposition from regulators and neighborhood groups -- looser development rules might work in its favor. A larger, denser population might stand to benefit more from tunnel systems. It also helps that Tesla is dramatically expanding its presence in China. The Boring Company could represent a convenient complement to the automaker's plans in the region.