In December, 2012, my wife (a non-bike tourist) and I rode a tandem on New Zealand's Otago Rail Trail. It runs for 90 miles between Clyde and Middlemarch in the south-central part of the South Island. While the usual time frame for riding the trail is 4 days (a fit bike tourist could easily do it in 2, if the wind wasn't blowing hard in the wrong direction), we decided to cut it down to 3 days.
We went along rivers,
past innumerable sheep, cows, and deer,
over bridges and viaducts,
and even saw a pretty sunset.
If you ever get a chance to do this ride, I'd highly recommend it. Here is my journal of the trip.