Sunauli is a dusty town that offers little more than a bus stop, a couple of hotels, a few shops and a border post. The border is open 24 hours and the crossing is straightforward, so most travellers carry on into Nepal without stopping here, pausing just long enough to get their passport stamped. Some move on to the nearby town of Bhairawa (officially named Siddharthanagar), while others get straight on a bus to Kathmandu or Pokhara.
Buses drop you just a few hundred metres from the Indian immigration office (and jeeps at its doorstep) – it's on the main road in the middle of town – so you can ignore the cycle-rickshaws. Don't forget to stamp in or out of India here!