The road and canal from Beijing to Nanjing used to have 46 post stations, and the 14th-century Yucheng station (盂城驿) in Gaoyou (高邮) is the best preserved one. This was for passing on letters as much as for letting the riders, boatmen, and horses rest.
The station with its halls gives a great look back in time. I’ve somehow really turned into a person who thoroughly enjoys this.
The area is pretty well preserved. If you squeeze your eyes it definitely feels like time traveling.
The canal is also still here, still heavily in use.
Marco Polo also wrote about Gaoyou (the city hasn’t changed names in over 750 years), and he’s also got a tiny monument here.