In West Bengal, India narrows to a tiny strip, squeezing between Nepal, Bangladesh and Bhutan before opening back out into the ‘Seven Sisters’ states of the far northeast. Here, the landscape sweeps from near sea level in the Brahmaputra Valley to the Himalayan regions of Arunachal Pradesh and Sikkim, spanning a huge range of topographies and ecosystems. Add to this one of the world’s wettest monsoons, and you get a cornucopia of wildlife – resulting in an estimated 50% of India’s total biodiversity.

In human terms, it’s even more complex – shaped by migrating Himalayan tribes, the rise and fall of princely states, the interference of tea-hungry colonial powers, and (more recently) migration from Bangladesh. The result is a cultural mix unlike anywhere else in India.

In Assam, you can stay at a colonial-era tea plantation, see one-horned rhinos at one of India’s most pristine national parks, and experience Mising tribal culture on a river island in the mighty Brahmaputra. In Sikkim, you can go trekking into some of the most spectacular mountain scenery imaginable, and visit Tibetan monasteries watched over by some of the highest peaks in the world. Beyond, there are the mysteries of the rest of the sisters, some of which are only just opening up to travelers after years of unrest.