It's always interesting exploring houses from another era. Wander around House of Victor Hugo and imagine how this historic house once was.
You'll have no end of sightseeing choices when visiting Besancon Old Town. House of Victor Hugo is an ideal place to start here, but there are numerous other worthy sights to explore. Besancon Citadel, University of Franche-Comte, and Micropolis Conference Center are not far from the historically significant residence and and will cap off your day nicely.