Many things .. 1) explore the ancient palaces of the maratha empire they include shaniwarwada . At the centre of the city,this will also give you an opportunity to roam the nearby places .
2)sinhgad fort-close to khadakwasla dam is am awesome weekend getaway for the puneri's . 3) exploring the nearby places such as lonavala,mahabaleshwar.
4) if you got plenty time you can also visit nearby beaches which are very clean and only 4-5 hrs from pune . alibaugh district houses no of beaches that attracts no of people from pune and mumbai
There are lot of things to do in Pune. You can start with Aga Khan palace, Shani war wada, Dagruseth Ganpati temple, Tulsi bagh, Parvathi hill, Osho garden, 7 wonders theme park, Imagica, Pataleshwar temple, Rajiv Gandhi Zoological park and many more.