Bhandardara is a mountainous region approx. 1400++ AMSL about 4 hours drive from Mumbai, maybe more depending on traffic and road conditions. Very close to Nashik.
From Mumbai you must take NH3 upto Ghoti which is a right turn just beyond Igatpuri, and keep going on the road till you reach Bhandardara. En route you will pass Bari village which is at the base of Kalsubai at 1650m AMSL, the highest mountain in Maharashtra.
The route is scenic but mostly barren and denuded due to continuous afforestation by the local villagers. The temperature drops perceptibly after Igatpuri. In the rains or in winter there is a distinct chill in the air. There is an MTDC, Anandvan hotel and a few other hotels at Shendi. MTDC faces the Arthur Lake.
Things to do: Take a gaoti ferry across the lake, visit Ratangad and Amruteshwar temple, Randha falls, Umbrella falls [in monsoons], climb Kalsubai or any of the other mountains in the vicinity, go for leisurely walks in the meadows, chase butterflies post monsoons, enjoy the wildflowers monsoons to Dec, and generally relax. You can visit the Ghatghar valley with prior permission.
Officially permission is not given to visit the Wilson dam, but unofficially it is possible. For those from Mumbai it is a pleasant change with cool weather. Best to go by your own vehicle which gives you flexibility to stop where you like and local travel. Otherwise take a train to Igatpuri or Ghoti and auto / bus thereafter . Hire an auto at Shendi to take you around.