O.K. Stop with Optimia for a while, and look, what is happening now at... for example Alexandria, the third largest city in the Imperium.
Year 257. The Decimus Scipio planned a great mission to the southwest, and Antonius cae Optimia is now Imperial General and Admiral. He will lead this grand mission. Look:
And the ships sailed. Many types, from trade ships to battle ships, they all were heading to the southwest. More than 18000 men.
The Sail continues 9 months, without any results. The Food stocks were smaller and smaller. Finally they saw land. But it was only small, lush island. They called it Island of Hope. They found many exotic fruits there, like bananas and coconuts, and the famine stopped.
They built big column, as a gift for the God and a small village with a little dock. And they continued...
But they sailed 6 months without any results. Any land. Only food for them were the animals brought on ships and fish from sea. This was not enough. And, something strange happened. Polaris star, what navigated them disappeared. And star signs were another too. The wind stopped to blow, so they started to use paddles. They were lost. The crew became scared after some time, because sea was much warmer, and they think, that the ships will fall from the edge of hemisphere-shaped Earth. But, they finally saw a land. Not a small island, but huge new land. They called it land of the Palms, because they saw thousands of palms on the coast. Land of the Palms, Terra Palmis.
After short sail slong the coastline, they found something shocking. A city. And that city was much more advanced than roman cities. This city was full of columns made of unknown and very solid metal. And it was abandoned. Nobody was there, and a city was very well preserved. Unnaturaly well. But interieur of buildings was destroyed, and it was decomposed. Windows were without glass, and trees started to grow in the buildings. City was abondoned very long time. All suggested, that it is Atlantis. But really?
Buildings were built from something more solid than "liquid stone" or bricks. There was also Arena and Coliseum. Architecture was amazing. City was not big, the wooden suburbs and farmlands were decomposed and consumed by forest and vegetation long time ago. They landed, and started a survey to the inlands. Land was more and more dry, and they entered huge desert. And they found there big village. It was abandoned too, but it was built from common materials. Somebody was recently there, maybe just yesterday, but maybe before 80 years. Buildings were not really damaged, and palms growing there were in lines. The lines had to be planted by man. And these palms were only 10 years old...
The flowers near two huge marble statues were from glass. One glass flower was worth big house in ancient rome, and there were hundreds of them. They took them to ships, and the most sailors sailed back to Alexandria. They were navigated by wind, what started to blow. And the rest of mission continued..