It's not always about walking under the shining Sun. The zillions of stars, the moonlight, cool breeze can also be an amazing combination to walk through.
Katraj to Sinhgad (Famously known as K2S) is a mountain range spread over around 15 KM between Katraj Old Tunnel & Sinhgad Fort. This range has about 16 hills & situated in southern areas of Pune. One can expect to get amazing night light views of Pune City from this route.