thanks for the link I will probably go with that idea I had always hoped that Kallistra would bring out a dedicated hex board with the rivers built in. They will probably release them after I do my rivers.
I have seen a guy on youtube that cut the large up a coir door mat using a 6 hex template so that his corn fields were built into the board, that is also on the to do list.
I bought some a few years ago, my idea at the time was to make rivers by cutting through the plastic and glueing sheet styrene underneath for the river surface, the river banks would be the thickness of the Kalistra tiles and the smooth surface of the styrene would be the water. I didn't get very far with the project for various reasons but it may be something that I come back to.
I did use the Kalistra bases for cavalry bases for 1/72 scale figures but over the years I found that they warp - effectively creating rocking-horses - so I don't do that any more.
Overall I like the Kalistra system and would like to do more with in the future.