Walking from Alcudia old town to the port
On a warm day you could take in the sights on the way there.
Old Polentia the Roman town (entrance fee),
the Roman Amphitheatre (free),
the beautiful cemetery (not sure if the churches are open but the cemetery is lovely),
the artistic roundabouts!!
Probably worth getting bus/taxi back though unless you walk back the other way via the shops:
Chinese supermarket containing everything you though you never needed,
Mercadonor, the cheapest local supermarket?
An excellent Feretaria, I can spend hours just looking for that exact hook you need!!
Electrical shops
etc
Too much really to fit in a day!!
Enjoy