Seen in Croatia. Nest of an insect?
No interactions present.
The pebbles in the material are bigger than anything an insect would be likely to carry. It is most likely to be clay or concrete that it is made of though.
how big is it?
It was about the size of a golf ball.
So glad to hear it's not concrete!
Lat/Lng: 42.95625, 17.10622