pixel_player18307119
Don't know why "you don't know where to look anymore".
Have you checked out the relevant Wiki pages in relation to this region????
The answer you seek is easily accessible, readily available & clearly defined.
https://wiki.diggysadventure.com/index.php?title=Story_Mines-China
https://www.diggysguide.com/china/tomb-of-the-first-emperor
It is clearly stated on the bottom of the maps created by @Roeland (which are contained in both the links provided above) that there may be upto 1219 tiles in the game scene of the Tomb Of The First Emperor (see attached screenshot).

This is a copy of a posting from an old thread back from October 2018
By @pixelplayer76738299:
In this particular mine, Tomb Of The First Emperor, the additional tiles may appear after a player solves the puzzle incorrectly. For this reason, there may be actually more tiles than the total amount that is displayed in the overview, and therefore a player can see the green check mark, although the mine has not yet been completed.
If anybody cannot find the missing tiles, you can either use the Last Tile Finder or contact Pixel support directly.
https://forum.pixelfederation.com/diggysadventure/d/173245-hero-of-china/7
Perhaps one of the moderators could create, post & sticky a "How to solve incomplete Hero Of China 49/50 issues" with relevant information, links, & screenshots as many players seem to be facing the same reoccurring issue? 😊