Going from India to Nepal, Nepalese visas are available on arrival. Going from Nepal to India? Hope you have visa already as no visa's are available on arrival to India. And neither immigration offices are overly helpful.
'''Via''' Dehli, Gorakpur, Sunauli, India/Belahiya, Nepal. 24 - 30 hours.
'''Via''' Kathmandu, Narayangarh/Bharatpur (var. Narayanghat), Butwal, Bhairahawa, Sunauli. 7 - 10 hours.
'''Via''' Pokhara, Palpa/Tanzan, Butwal, Bhairahawa (potholed, windy road, but beautiful views) 5 - 6 hours. Also Pokhara, Narayangarh/Bharatpur/Butwal, Bhairahawa, Sunauli (better road conditions). 5 -6 hours.
'''Via''' Gulmi-Tamghas, Palpa/Tansen, Butwal, Bhairahawa (potholed, windy road, but beautiful views) 4 - 5 hours.
Do not book a ticket in kathmandu from AMAZON TOURS & TRAVEL,INDICA TOURIST POINT and PAUL TRAVEL (in Varanasi) that are working with SIGHT NEPAL in sunauli on the nepalese border. You pay alot for them in the end to put you on local buses where you get stuck for 10-12 hours and are dangerous. We got to Sunauli in one piece and were going on our second bus to varanasi what we been promised to be safe and comfortable. SIGHT NEPAL told us that a guy on the indian border would meet us up to show us our bus and help us. First he had the worst attitude and started to get angry when we didnt want to give him our tickets when we saw what he said, was our bus for 12 hour. It was the worst thing you can ever imagine! We didnt want to give him our tickets because he would just walk away and cash them in for money or sell them to somebody else for a crazy price. When he finally showed us a better bus but still a localbus, he wanted to have money from us by charging for our bags on the bus. We didnt give him a penny and the bus finally drove off without them which proves that they just wanted to rip us off entirly. Dont take bus to india from the border but go to gorakhpur and book ahead for train there.
'''Via''' Kolkata, Patna, Gorakpur. Transfer to narrow gauge track to Nautanwa. Transfer to taxi/bus/rickshaw to Sunauli, India (approximately 5 kilometers). Cross border to Belahiya, and Nepal's Immigration. Total time approximately 10 - 12 hours.
Rickshaw's, buses, taxis all available. If you are stuck overnight here do not hesitate to take a 10 minute rickshaw up north for wonderful restaurants in Bhairahawa.
Most of the accommodations are found on the Nepal side, though there is a Government of India run hotel for pilgrims on the Indian side. Look for the large white building about .5 kiilometers south of the border on the main road. Modern rooms with bathrooms, TVs, and A/C for 1200IRs. None are recommended for women travelling alone. . Cheaper rooms usually go early in the day.
Options for food on the Indian side of the border are very limited and of questionable standards (with the exception of the pilgrim's hotel). Eat on the Nepal side and/or pack extra food if possible. Look for nice little outdoor daba/tandori restaurant run by Lucky Singh just 30 meters north of the border on the east side. Questionable atmosphere but great food! They even have A/C facilties (20 NRs extra) in the hot season.