For my historic build in Minecraft I decided to go with a very round structure with many arches. Because why not, I figured I could make it work with a variation of blocks, slabs, and stairs. To start I looked up images of the Colosseum in order to look at while building. Based off the old light brown material I decided to use sandstone as my main material as I felt it represented the real structure the best
Since the Colosseum is a bunch of repeated layers of various arch designs, I figured the first step was to build a simple arch and then duplicate it around the base of the structure.
Next I built up four and a half stories up on one side and two and a half on the other based off the picture. Putting torches in hidden places behind the arch so that at night it would look just like the illuminated picture above.
When it came to the sides I managed to come up with a really cool structural design to represent the inner support of the Colosseum. I had to create something that went from the ground to the third story. I couldn't just make a straight pole as the support in the Roman Colosseum snakes up and creates a tunnel like walkway on the second floor.