Fly to Kolkata, a vibrant city in the far east of India. Depending on your time of arrival the rest of the day is yours to start soaking up the local culture.

The capital of West Bengal and widely considered India's cultural capital, in Kolkata is a place of fascinating contrasts, something that you will explore on today's tour of the city. See landmark sights like Birla Planetarium, Belur Math, Dakineshwar Kali Temple and the spectacular white marble edifice of the Victoria Memorial before, this evening, taking a walking tour to Park Street, the famous thoroughfare in Kolkata's downtown area.

The capital of the British Raj between 1858 and 1911, Kolkata is home to a series of colonial sights which you will visit on this morning walking tour, including the stately Dalhousie Square. This afternoon, you'll pay a visit to Mother House, a quiet convent that was home to Mother Teresa and her missionary sisters since 1953. Visit her tomb and a small museum dedicated to her life and work.

Transfer to the airport and fly to Bagdogra. On arrival, drive to Gangtok, winding through the incredible landscapes of Sikkim, with towering Himalayan peaks as your backdrop.

Sikkim's bustling state capital, Gangtok sits on the side of a hill overlooking the valleys and peaks of the Himalayan foothills. Today you will explore it, visiting the 18th-century Rumtek, the region's most spiritually significant monastery, Enchey Monastery with its colourful prayer hall, the Tashi Viewpoint, where you'll get spectacular views of Mount Kanchenjunga and more. You'll also fly your way up the cable ropeway for panoramic views of the city and its surroundings.

Soak up the incredible scenery as you travel through the Himalayan foothills on Christmas Eve, passing through vast expanses of tea plantations as you approach the hill station of Darjeeling. En route, you'll stop at the Ravangla Buddha Park to admire a 40-metre-tall copper Buddha set against a mountainous backdrop. You’ll find Darjeeling festooned in festive cheer, with twinkling lights, colourful decorations and Christmas trees, the colder climes and snowy mountain views adding to the Christmas ambiance. This evening, enjoy a Christmas Eve dinner before an atmospheric midnight mass in a local church.

Merry Christmas! Start the day in spectacular fashion, travelling up Tiger Hill to watch the sun rising over the 8,586 metre Kanchenjunga (weather dependent) – if you’re lucky there might even be a sprinkling of snow! Sit down to a hearty Christmas lunch before an afternoon ride on the Darjeeling Himalayan Railway's 'toy train' from Darjeeling to Ghoom. Visit Ghoom Monastery before returning to Darjeeling to tour the Padmaja Naidu Zoological Park, the Himalayan Mountaineering Institute and Tibetan Refugee Center. This evening, enjoy a stroll through the lively Christmas market.

Transfer back to Bagdogra airport and fly to Guwahati. The rest of the day is at leisure.

Transfer to Silghat, a port on the Brahmaputra River, where you'll board your river cruise vessel. With a spa, saloon, and spacious sun deck along with cool and roomy cabins with floor-to-ceiling sliding windows for optimum views, there is no better to explore the rich riverbanks of the mighty Brahmaputra. Cast off and begin your upstream cruise, enjoying lunch and dinner onboard.

This morning, disembark from the ship and take a jeep safari into the central range of the Kaziranga National Park. A UNESCO World Heritage Site, Kaziranga is best known for its population of Indian rhinoceros and is a designated tiger reserve. Alongside these two magnificent creatures, Kaziranga is also home to elephants, sloth bears, pangolin, water buffalo, swamp deer and a number of species of primate, among much more, and is an important habitat for birds. Enjoy a riverside lunch before hopping back into jeeps to explore the park's western reaches, where there is even more wonderful wildlife to spot.

Spend the morning on a tea experience on a picturesque Assam tea estate. Here you’ll learn all about the production process, from plucking the leaves to brewing a cup. Back on the boat, cruise upstream, passing through more of Kaziranga National Park's spectacular wilderness, spotting wildlife on the banks of the river as you go. Drop anchor near Biswanath village.

Head into the village, where there is a rich, cultural heritage to explore. Biswanath's ghat is home to a cluster of temples dedicated to different gods, including an Ahom-era Shiva temple – discover these and have a wander through the town, soaking up the beautiful riverside and rural surroundings. Continue cruising through Kaziranga National Park, keeping a look out for wild elephants. Then, spend the afternoon up on the ship’s sun deck where you may be lucky enough to spot a member of a small population of the endangered Ganges River dolphins.

Today, New Year’s Eve you'll be able to sit back, relax and watch the river landscapes drift by as you cruise upstream. There will be one stop at a rural riverside village where a walking tour is a great way to stretch your legs. This evening, you’ll be served a celebratory dinner with a cheers at midnight – what a way to see out the old year and see in the new one!

Happy New Year! Explore one of the world's largest river islands, Majuli, which is a fascinating microcosm of local culture. Visit two of the island's tranquil satras (monasteries) that have been essential in preserving Assamese art and culture and enjoy a traditional dance performance. Cruise farther upstream to Salmara Ghat, visiting a nearby village that is known for its traditional handicrafts, to see the artisans at work.

Transfer by car to Sibsagar. Once the capital of the Ahom kings, explore the remnants of a fascinating culture with visits to old temples and examples of innovative engineering. Return to the ship and cruise back to Neamati Ghat for your final night onboard the ship.

Bid farewell to your river cruise ship and transfer to Jorhat airport for your flight back to Kolkata. The rest of the day is at leisure.

Fly home to Australia, arriving the same or the following day.