I’ll jump in.
Around Burlington, my Burlington Liar’s Club series (GCW95Z) is a unique urban series if you are looking to spend some time in a small town. If you want hiking around Burlington, Ridge Runner (GCJ00W) and General (GCTEZ9) are both on the same ridge trail overlooking a marsh. I also can recommend How Did You Start Geocaching? (GC10FM2) a little farther away.
In Bong, my favorites are Poof! (GCJGFD), Horsing Around (GCNG9V), Wildlife Stalk (GC111A7), and Captain Klutz (GCR6CG). Additionally, you might want to stop by Lumbering Along (GCHM9N) for a fun container hide, and “I’m On Top” (GC14255) for a trendy container hide that you might not have seen yet. Note, however, that if your goal is numbers, these caches are the exact opposite of what you want. These all involve hikes and some terrain. If numbers are your goal, just start at the Visitors center and head for the nearest cache. There is a ton of them out there in most parts of the park, so just cache away.
Have fun! (Oh, and I won’t be physically able to do Bong on that day, but otherwise I would have loved to join you.)