Just to be different:
"Wobble World," a low-magic setting on a high-silicon planet with severe polar tilt, short days, and long years, so the poles get quite hot for weeks in the summer, quite cold for weeks in the winter; and the high silicon content leads to lots of glass content in the rocks. Glass is a non-crystalline solid; that is, it tends to flow slowly, but still moves much more easily than crystalline rocks.
The resulting continental drift would be quite perceptible. It might take a mere 1000 years for a tropical location to become temperate, or a temperate location to become polar.
People would have to be on the move often. Cities could be built if they were built fast; but cities would have to be abandoned occasionally as they got closer and closer to the poles.
People on the move would come across relics of ancient cities that had moved down from the poles to the temperate regions; and the people might be puzzled by inscriptions such as, "My name is Ozymandias, King of Kings. Look on my works, ye mighty, and despair."
Edit for clarification: So, everybody would be able to find ruins. Every culture would have to move from time to time. Few cities would be more than 3000 years old. There would be lots of ruins to explore; hence, being an explorer wouldn't be too weird.
Edit edit: Inspired by Jack Vance's "Big Planet" more than anything else.