For more than a decade, about 100 000 Bhutanese refugees forced out of that benign gross-national-happiness country of Bhutan have been sitting in Jhapa waiting for a solution to their question of repatriation. The second generation refugees are now coming up - children who have known no other existence than the camps. The camps are supervised and provisioned by the UNHCR, but it diesn't replace the freedom of settlement and taking work and generally progressing with their lives.
I do not mean that you should do refugee camp sightseeing, but just be aware of this situation. A few places in Jhapa you can see the camps from the road, but generally they are a bit away from view. To enter you will need a permit from the relevant district authorities.
There are many tea gardens in Jhapa, and they provide the regular teas served all over Nepal. This lowland teas are less distinct than the highland qualities from Darjeeling and Ilam, but still good. With some luck you will be able to connect to an estate manager who can show you around.
Charali isn't much of a town, it is a crossroads town of the Chandragadhi-Ilam route on the Mahendra Highway, just 8 km from Kakarbhitta, the Indian border crossing. Mandro serves good food in clean surroundings, catering both for locals as well as Nepali travellers. Foreigners are far and few between here, but their menu is also given in English text. If you for some reason aren't able to make it to Kakarbhitta for the night, condsider staying and eating here. As many travellers are hill people, you will also find good hill food, tea, beer etc. You won't be at loss. I have eaten here many times before setting out for Ilam, never disappointed.
They can assist you with ticketing, jeep reservation, hotel bookings etc. also, their travel agency next door.
Their facilities are vastly upgraded over the years, and now cater for a larger influx of travellers. Still, you do not get the bus crowds here, because it is located a bit up the road from the East-West Highway.
Favorite Dish: Momos are a hit as always, and Mandro is known for them.
If you lost your flight or came too early, or have business to do in Chandraghardi/Bhadrapur, then the Hotel Friendship Restaurant and Bar is the best place in the town of Chandragadhi. They cook up decent meals for a reasonable price. Ask what is easy and fast before you order, otherwise they may have to go out and catch fish and fowl for you and start with the live raw material. They do decent mutton and chicken curries, and the beer and soft drinks are cold. Better eat a full meal here if you have the time rather than at the snacks eateries at the Bhadrapur airport.
Favorite Dish: Good chicken daal bhat. Good noodle dishes.
There isn't a whole lot of safe things to do in Jhapa's streets and bazaars after dark. As dusk settles, have a fanned corn on the cob at the curbside, but hit the indoors soon thereafter. Everything closes early anyway and with army and maoist presence still, both likely to take advantage of still-open businesses and congregations of people, the best option is to watch the tropical sky from a terrace and have some food and drinks while the cities and villages close down for the night.
Dress Code: Dress against mosquitos....
The only viable airport is Bhadrapur (code BDR). Four airlines fly here from Kathmandu. There are no international links or regional links. For links into the hills you need to move on to Biratnagar...
The biggest problem doesn't seem to be getting to birtamod, but to get away from there... The best assistance I have managed to obtain in order to get out of there is via Mohan Silwal of Laxmi Travels. The counter of Laxmi Travels is located on the corner of the Mahendra Highway and the Birtamod - Chandragardi road. While the office is modest, the tentacles are long and the phone calls numerous - you will get that last seat on the flight out of Bhadrapur - if there is one. I use this agent for jeep bookings, bus info and air travel services, confirmations and changes. They are very good at it and the price is fine.
The Terai in general and apparently Jhapa in particular seems to be the base of numerous squadrons of mosquitoes, many of them carrying malaria... Just be forwarned. If you are transiting Bhadrapur and will head into the hills, do take care to cover up. If staying for any amount of time during rains or other humid conditions, do take malaria prophylaxis.