Is it possible today to build a pyramid, a Roman pantheon, and a wall like the great wall of China?

Question

Were they considered wonders only back then? Or are they still considered architectural wonders till today? Is it hard to build such things nowadays?

Answer 1

As all have been built, it must be possible.  They were all intended to be monumental and objects of wonderment.

The pyramids were statements about the people who ordered them to be constructed: "I'm important whereas the rest of you are worms".  However, they were also intended to be functional.  In terms of Egyptian mythology you could think of them as being akin to spaceships; high-tech vehicles to convey the only important passenger to his new abode, and to do so with all the creature comforts his immortal nature entitled him to.

The Pantheon in Rome is somewhat different, as that building underwent a serious of developments and rebuilding.  Undoubtedly, the people giving the orders wanted it to be the best it could be, seeing as it was an important public building in the most important city in the world, and they could show off the amount of money they could squander on the thing.

The Great Wall was primarily intended as a defence structure to keep the barbarians out and, as is common for such devices, it ultimately failed.  The problem with defesive walls is the staffing they require.  Still, making the building extravagent also made a statement about the power and importance of the Chinese Emperor and, an added bonus, it gave a message to the presumed barbarians: "You can't possibly get past this massive wall, so you may as well not bother trying."

Eventually, the Mongolians begged to differ.