Pumice construction Ltd.
A construction company run by Proteans and Dotters of Tartarus. They have amazing technologies that has shaped society.
They have a special concrete production method that allows them to shape and colour concrete in amazing ways. This has led to the boom of post modern brutalism. Additionally, they can easily melt concrete back to a liquid form allowing them to constantly change and/or replace buildings with relative ease.
For roads and foundations they are able to make a tough wearing igneous rock from lava and water.
These are energy hungry practices but with the abundance of nuclear energy in the world it is not an issue.