Kinshasa's N'djili Airport has relatively few international connections for a city of its size. There are even fewer services to the airports in Goma and Lubumbashi.
Airports & Airlines
The three main international airports in DRC are in Kinshasa, Goma and Lubumbashi. None of them is particularly pleasant, but Kinshasa is definitely rather a headache, especially if you're flying domestically. Count on lots of hassle, frequent demands for bribes, tough security and long lines.
Since 2015, Congo Airways has been the DRC's national carrier, taking the place of former national airline Hewa Bora, which ceased operations in 2011.
Ethiopian Airlines Also fly to Goma and Lubumbashi.
Kenya Airways Also fly to Lubumbashi.
DRC's departure tax is US$15/50 for domestic/international flights and needs to paid in cash at the airport. You will also need to purchase something called a 'go pass' for all flights. This is currently US$5 and is paid at the same time as the departure tax.
Angola Take a boat to the Angolan port of Soyo from either Boma or Muanda. Buses then connect Soyo to Luanda. If you're driving to Angola, the easiest route is via Luvo, where the road is better than that from Matadi.
Burundi Various bus companies run from Bukavu to Bujumbura (Burundi) via the border at Gatumba.
Central African Republic The border with CAR was closed at the time of writing.
Rwanda Whether you're heading to Goma or Bukavu, normally crossing from Rwanda couldn't be any easier. Transport from Kigali to the border towns of Gisenyi and Cyangugu is frequent, and from there you just walk into DRC and hire a moto-taxi to take you to your destination in town. In the case of Gisenyi, you cross directly into the city of Goma, and can even walk to your hotel.
South Sudan The entire border region with South Sudan is considered unsafe and should avoided, though the border with South Sudan at the remote town of Aba is open.
Tanzania There is no land border with Tanzania, so your only option to go directly from DRC to Tanzania is to cross Lake Tanganyika. Head to to the port of Kalemie and try to negotiate passage with a cargo boat to Kigoma.
Uganda The principal route to Uganda is from Beni to Kasindi, where you walk over the border and get another taxi to Kasese. Tour guides in Kisoro sometimes take clients across at Bunagana to see Parc National des Virunga's gorillas at Djomba.
Zambia The main crossing is just south of Lubumbashi at Kasumbalesa, and it's safe and straight forward to cross here. Take a taxi to Kasumbalesa and walk across the border. Once across, take a shared taxi to Chingola, from where there are buses to Kitwe and Ndola.
Republic of Congo
Crossing the Congo River between Kinshasa (the port is called Beach Ngobila, or just 'Beach') and Brazzaville ('Le Beach') can be a real headache. It helps to travel in the afternoon and on weekends when the crowds are thinner. The crossing involves taking a canot rapide (speedboat), which takes ten minutes and costs US$25. Boats sail 8.30am to 4pm Monday to Saturday, and until noon on Sunday. Boats usually don't run on holidays. Although these journey times make it look like you'll be done and dusted in an hour or so, they don't take account of the extraordinary amount of general time-wasting that takes place. In reality you need to allow at least a half-day to complete all formalities and cross the river – sometimes even longer.
On both sides officials will want to know exactly how many phones, cameras, computers and how much cash you have with you – declare everything. Various 'taxes' and additional 'fees' add at least US$30 to your journey. There's no point being stubborn and trying to avoid these. Because of the lack of signs and the abundance of hustlers, many people pay a fixer to get them through the process. While that's not strictly necessary, it can save you a lot of hassle and anxiety. However, be aware that some of these fixers can have their own scams going on, and others are widely disliked by the immigration and customs authorities and can actually be a hindrance to your passage across the Congo! If you arrange a fixer through a recognised tour company or hotel you can expect to pay around US$70 for their services, and they will deal with all the 'problems'. Some travel agencies can arrange for 'VIP' crossings, in which the hassles are far reduced.
If you're driving, there is currently no car ferry between Brazzaville and Kinshasa, as the last one sank and hasn't been replaced. Overlanders therefore have to take the massive detour via Kinkala and Boko (Republic of Congo), then Kimpese (DRC), crossing the river with the car ferry at Luozi or Pioka. The officials here are relaxed and the immigration and customs process is mercifully simple, but the road is awful and requires a decent 4WD in the dry season. In the wet season it's often close to impassable. Motorbikes travel free on this route and cars pay US$15.
Being landlocked, there are no scheduled services that allow you to arrive in DRC by sea.