The most visibly impressive element of modern reinforced concrete built environments is of course skyscrapers. In just a century, the height of the tallest building 5xed (after only increasing 10% between pyramids and 1900).
But tunnel systems are arguably way more impressive.
Conversation
Replying to
Ever been to Singapore? They got entire underground malls there, with well thought out layout and links, naturally.
1
Replying to
Yeah but weather is nice there so you’re not forced underground as much. Went to Seoul in winter.

