Introduction to the Time Tunnel: The Time Tunnel has the "Fortress of Cao Wei" in the north and the "Remains of Tunshu" in the south. The meaning is that one is to return to the Three Kingdoms period through this time tunnel in the 21st century, and the other is that We have walked into Hefei New City, a military castle during the Three Kingdoms period. Through the transparency of the glass, we can truly see the cross-sections of the different soil layers used to build the city walls during the Three Kingdoms.