Travelling By Land All Over the World

Russia is planning on building a tunnel from Russia to Alaska to allow the transport of both goods and power. Though it wouldn't be cost effective, you could theoretically travel from South America to North America to Asia, Africa, and Europe by train once this was built. (Yes, you'd still need to fly or take a boat to reach Antarctica, Australia, and other islands). They're saying investment could be paid back in 20 years.