About 1.5 miles north of Hawes is 30m-high Hardraw Force, the highest unbroken waterfall in England, but by international standards not that impressive (except after heavy rain). Access is via a lovely landscaped walk (400m) from the car park behind the Green Dragon Inn. There's an admission fee (cash only) to access the walk, and a cafe selling local ice cream.
Hardraw Force
Yorkshire Dales National Park