My Lands: Black Gem Hunting

I found a flag but its not showing in any of my bases what should i do ?
Is it possible its there but not able to see it ? thanks

It's not in a pit? The only other thing I can think of is that it's been stolen, but you'd know about that...

the flag should have been placed in the Main Building of the city of your explorer. If it`s not there ask the in-game support - they will help you.