Short answers, pulled from the story.
The earliest confirmed purpose-built structures in human history were simple post-hole alignments discovered near the village of Chichibu in Japan, dated to approximately 500,000 years ago. These pentagonal arrangements of holes suggest that Homo erectus constructed two huts, marking a pivotal moment where hominins transitioned from utilizing natural rock shelters to actively engineering their own environments.
The Great Pyramid of Giza was built for Khufu between 2589 and 2566 BC. It stands as the last surviving wonder of the ancient world, its core structure covered in polished white limestone and topped with gold, a testament to the engineering prowess and religious devotion of the Old Kingdom.
The Doric, Ionic, and Corinthian orders were distinguished by their columns, with the Doric being stout and basic, the Ionic featuring four scrolls called volutes, and the Corinthian adorned with acanthus leaves. Contrary to the modern perception of these buildings as monochromatic white stone, ancient temples like the Parthenon were originally polychromed with vibrant reds, blues, and greens.
The Gothic style began with the Basilica of St Denis around 1135. It introduced the pointed arch, ribbed vault, and flying buttress, allowing for taller buildings with larger stained-glass windows that filled the space with colorful light.
The earliest Baroque ideal city was Zamość, built north-east of Kraków by the Italian architect Bernardo Morando. It featured a centralized town focusing on a square with radiating streets, serving as a manifestation of power and authority on the grandest scale.