Our driver weaved expertly through the traffic – gaudily painted buses, auto-rickshaws piled high with boxes, mopeds carrying entire families, sacred cows. Finally, we left the cacophony of honking horns behind us and were passing through sleepy villages where women in vivid red, orange and pink saris stood out against the emerald-green, post-monsoon landscape.
A few hours, and a world away from the mega city of Mumbai, Hilton's first leisure hotel in India is an all-villa retreat in the bucolic setting of the Western Ghats, a spiny mountain range cloaked in evergreen forest and surrounded by rice fields and bamboo plantations.
The De Souza family has been acquiring uninhabited land in the historic Maval area for years and now the estate spans 3,500 acres. They had an ambitious vision for a hotel with an emphasis on wellbeing and relaxation, that would also help to preserve the area's ecological and cultural heritage via the Shillim Institute, which offers workshops, courses and discussions as well as cultural exchanges and conservation programmes. However, with no experience of hospitality, they partnered with Hilton to realise their vision.
Banish thoughts of a bland business hotel; the 99 contemporary villas spread across the Spa Zone and Lifestyle Zone were built from local stone and designed to sit comfortably in the environment. There's no ostentation, just clean lines, neutral tones, space and seclusion. No trees were felled during construction, in fact thousands of endemic trees and shrubs were planted to attract hundreds of local bird species.
Shillim's watchwords are conserve, sustain, heal and enjoy. Electronic buggies are available to ferry you back and forth across the hotel's 320 acres. The hub is the Clubhouse, decked out in lots of dark wood with quirky light fittings. It's home to the library-lounge, the indoor-outdoor Terrazzo restaurant, the Valley Bar and The Reserve, which will be India's largest wine cellar when it's fully stocked.
The menus allow you to indulge in rich curries or Mediterranean-Asian fusion dishes, or be health-conscious with wheatgrass shots, vegetables and herbs plucked from the organic farm garden and local produce tailored to your own Ayurvedic dosha at the Spa Zone's Green Table. Cocktails strike a happy balance, such as the detoxing cucumber ginger martini.
In the vast Spa Zone there are 17 therapy rooms and a list of around 150 treatments that tick off massages, scrubs, wraps and facials, as well as Ayurveda, acupressure, yoga and meditation and longer courses with visiting masters skilled in pranic healing and hypnotherapy.
You can start the day with a class at the open-sided yoga pavilion and end it staring into the flickering flame of a candle in the estate's contemporary take on a meditation cave. Sweat it out in the steam room, sauna and hot tub or cool off in the huge swimming pool. For the active, there's biking, riding and trekking.
Early one morning, I trekked up to Shillim Peak, the estate's highest point, arriving on top of its grassy plateau to find breakfast laid out with a background of show-stopping views.
It's a three-hour drive south-east from Mumbai, if you avoid the rush-hour. Once you pass Lonavala, a hill station on the road to Pune, the road becomes incrementally more scenic until you're in the midst of the northern reaches of the Western Ghats. You don't have to leave the estate to go mountain biking, hiking, horse riding, paragliding or fishing in the lake, and ancient hilltop forts and Buddhist caves are a short drive away.
The estate has a helipad for jet-set arrivals and sea plane transfers – landing on Lake Pavna, within the estate – are in the pipeline, which will cut the journey time to under an hour.
There are 99 spacious villas: Spa Pool Villas, Spa Villas, Forest View Villas and Valley View Villas. They all come with private decks or balconies, spa treatment areas and floor-to-ceiling windows. My Spa Pool Villa was a picture of exposed rough stone walls, polished stone floors, white ceilings and dark-wood furniture. Along with all the hi-tech kit – a 42-inch TV, iPod dock and espresso machine – the bed was four-poster, the living room's contemporary furniture was covered in tactile materials and billowing white curtains lined the windows. The sleek, grey slate bathroom's made-for-sharing bath and open shower looked out over a garden complete with loungers, an alfresco shower, and a heated pool where I tried out Watsu, a touchy-feely, water-based Shiatsu.
Hilton Shillim Estate Retreat Pawana Nagar Taluka Maval, Pune, Maharashtra, India (00 91 21 14712 468; shillimretreatandspa.hilton.com).
Villas start at US$400 (£267), with breakfast.