There are some very interesting parts of Amiens, river-side restaurants, some gardens surrounded by small canals (and you can get boats to have a look around), some lovely green spaces, and somewhere an English-style garden. The centre of Amiens has some nice buildings, including the Cathedral, and years ago the railway station restaurant was really good!
It's not an area we've spent that much time in - sometimes just a stop-over on our way south, and it's some years since we were last there, however.
There are also all the war memorials around the area, and you're not that far from Paris should you fancy a day trip.