Depending on the population of the travellers, they’re first hand sources of what would be ancient history. There is nothing more valuable. What life was like, what people did, why the decisions were made, what consequences did the creation of such a program have, what was the architecture really like, what was popular media, what was popular comedy. The historic cultural aspects alone would write books.

God Id take a pay cut and change careers to get a chance to interview ancient Egyptians if we had a clear way to communicate.