The Forest That Boils: Semuliki, Where the Congo Slips Quietly Into Uganda

The steam finds you before the path does. You are walking through lowland forest west of Fort Portal, listening to the metallic clatter of a piping hornbill somewhere above the canopy, and then the air changes — thickens, sweetens faintly with sulphur — and through a screen of raffia palms a white column rises two metres into the morning and drifts sideways into the trees. This is Nyasimbi, the female spring at Sempaya, and she has been boiling for as long as anyone in Bundibugyo can remember. Guides carry eggs in their pockets for the demonstration. Ten minutes in a woven basket lowered into the water, and breakfast is ready. The water runs at around 100 degrees Celsius. Nobody puts a hand in twice.

Semuliki National Park is the least visited of Uganda's national parks and, by a good margin, the strangest. It covers just 220 square kilometres along the floor of the Albertine Rift in Bundibugyo District, hemmed by the Democratic Republic of Congo to the west and the glacier-topped Rwenzori Mountains rising to the south-east. Geographically it belongs less to East Africa than to Central Africa: this is the far eastern tongue of the Ituri Forest, the great Congo Basin rainforest that reaches across the border and stops here, at the Semliki River. Everything that makes the park remarkable follows from that single accident of geography.

Botanists have called Semuliki one of the oldest and most biologically rich forests in Africa, a refuge that stayed wet and wooded through the dry glacial periods when much of the continent's forest cover retreated. What survived here survived nowhere else nearby. The result is a bird list that reads like a Congolese field guide dropped into Uganda by mistake: some 441 species recorded, of which 46 are Guinea-Congo biome specialists found in no other part of East Africa. Birders come for the white-crested hornbill, the red-billed dwarf hornbill, the African piculet, the Congo serpent eagle, the spot-breasted ibis, the swamp palm bulbul, the lyre-tailed honeyguide. Great blue and Ross's turacos flash indecently through the mid-storey. Out on the Lake Albert flats at Ntoroko, in the papyrus at the river mouth, the shoebill stands like a badly assembled statue and lets boats drift close.

The mammals are harder work. Around sixty species are present — forest buffalo, sitatunga, water chevrotain, bush pig, several kinds of duiker — but this is dense lowland forest and sightings are a matter of patience and luck rather than schedule. Eight primate species live here, including chimpanzees, red-tailed monkeys, grey-cheeked mangabeys, black-and-white colobus and the nocturnal potto. Visitors arriving expecting a game drive misunderstand the place. Semuliki rewards walkers, listeners and people willing to stand still in humidity.

Most visits begin and end at Sempaya, where the two hot springs sit about half an hour apart on an easy, well-made boardwalk-and-forest circuit that takes roughly an hour with a ranger. Nyasimbi, the female spring, is the geyser — the one that erupts and steams and boils eggs. Bintente, the male spring known locally as Mumbugu, is calmer and stranger: a twelve-metre pool of hot water lying in a swampy clearing, steam sliding across the surface. For the Bamaga people these are not scenery. The springs are a shrine; men have long come to the male spring to ask for wealth and blessing, and sacrifices are still made. Good guides tell that story properly, and it is worth asking for.

Beyond Sempaya, the park opens up for anyone with time. The Kirumia Trail is the serious one — roughly thirteen kilometres through primary forest to the Semliki River, a full day out and the best birding walk in the park, starting early and finishing muddy. The Red Monkey Track follows the eastern edge along the Semliki towards the DRC frontier, named for the de Brazza's monkeys that haunt it. Shorter circuits run from Ntandi, where you can also meet Batwa communities whose ancestors lived in this forest long before it was gazetted, and whose displacement remains part of the park's unfinished story. At the northern end, Lake Albert and the Semliki flats offer boat trips, fishing villages and the best shoebill odds in western Uganda.

Getting there: Sempaya Gate is about 52 kilometres from Fort Portal on the tarmac road to Bundibugyo — two to three hours, spectacular where it drops off the Rwenzori escarpment, and full of humps and blind corners. Fort Portal is roughly five to six hours from Kampala. The park pairs naturally with Kibale, the Tooro crater lakes or a Rwenzori trek.

Fees: Semuliki is a Category B park. Entrance is USD 35 for foreign non-residents, USD 25 for foreign residents and UGX 15,000 for East African citizens, with most guided activities charged separately at around USD 10 (UGX 10,000 for EAC). Confirm rates at booking, as tariffs are reviewed on a cycle.

When to go: The drier windows of December to February and June to August make the trails manageable; this is one of the hottest and most humid corners of Uganda, and the long-rains months turn the Kirumia Trail into a wade. Birding is good year-round, with migrants adding weight from November to April.

Where to stay: Options are modest and few — Semliki Safari Lodge in the Toro-Semliki Wildlife Reserve at the upper end, Ntoroko Game Lodge on Lake Albert, Nyati Game Lodge and a handful of guesthouses and campsites around Bundibugyo and Sempaya. Many visitors simply base themselves in Fort Portal and drive in.

What to bring: Binoculars, a Congo-inclusive bird guide, waterproof boots, insect repellent, and more drinking water than you think you need.

Late in the afternoon on the Red Monkey Track, the forest thins towards the Semliki River. On the far bank the trees begin again and do not stop for a thousand kilometres. There is no fence, no post, no line — only water the colour of milky tea, and the sound of voices carrying across from a Congolese fishing camp, and hornbills moving between two countries without noticing either. It is a good place to remember that Uganda's borders were drawn across an ecosystem that never agreed to them, and that Semuliki exists because a small piece of the Congo happened to fall on this side of the line. Fewer people come here in a year than pass through Bwindi in a month. That, for now, is precisely the appeal.