In the Seven Seas expansion, there is a card called Ice Floe, but the text doesn't match the image, which is why I couldn't find it earlier today.
The text says:
Ice Floe: UCN: UCN: 18 Any Ship loose one Power Stone to enter this terrain. (Artwork: Pennington, Text: Philbarfly, Design: Cath)
But here is the image:
So losing a Power Stone to enter terrain isn't bad. On the other hand, reducing Rivers and Lakes bonuses to zero is just silly. They get reduced to zero when a Shield is on any Terrain other than Rivers and Lakes.
I suppose it could be useful, and I'd have to check every card, if there were some other card that allowed R&L bonuses to be applied to combat, but didn't change the terrain (e.g., the Overlord card would change the terrain to R&L).
Yes, I feel better. Thank you to jackalwere for pointing this out on the earlier thread today.