[1125]

The caption of the last image says: "Visitors can tour the system, which cost $2 billion and was completed in 2006." I hope that's just a typo.

[klodolph]

What part do you hope is a typo?

[sp332]

Tokyo has a GDP of $1.6 trillion per year. And they have a lot of expensive property they want to protect from flooding.

[CognitiveLens]

Quick lookup of other sources all state figures between US$2billion and US$3 billion

[sxates]

I initially read that as the tour costing $2 billion. Seems a bit steep!

[segmondy]

Is it? How much have the recent floods experienced in the Americas cost?

[mholt]

Yeah I wouldn't want to pay $2 billion for a tour.