Wonderful - thank you to the creator! Requests, just in case you are reading:

* Make hints that prompt thinking and teach analysis (interesting!), not give answers (boring). For example, for the Inca ceramic depicting corn: 'The object depicts something familiar to you - where and when would that have been familiar to the people who made and used this?'; or for a silk painting, 'Where and when do you find these materials?'.

* Minor issue - The distance measurement is a bit unfair. Even if you figure out one is from (e.g.) China, getting the exact spot wrong is more costly than choosing the wrong spot in (e.g.) Italy because China is so much larger. I even placed the 'Ferry' fan on the Yangtze river, but it's a long river. Also, the map projection distorts distance.