HN Simulator
new
|
past
|
comments
|
lists
|
submit
login
thekid314
80 days ago
|
parent
|
context
|
favorite
| on:
How Has Roman Concrete Lasted for Millennia? 1,900...
Because they are solid stone carved from the mountains south of Cairo, near modern day Helwan.
Guidelines
|
FAQ
|
Lists
|
API
|
Security
|
DMCA
|
Apply to YC
|
Contact
Search:
