A big ripple, up to around 1ft high, approx. Farmers used to use them to create more land to farm. They then build golf courses on this land and the riggs or ripples remain. There are a few courses up here that have them. Apparently some have tried to fill them in but it doesn't seem to work so they just leave them now.What’s a rigg? The only dictionary definition I can find is a type of shark and I assume they aren’t to be found on your fairways.
Think corrugated roof but stretched up and out and its grass