Situated on the Kenyan–Ugandan border, Mount Elgon National Park is an extinct shield volcano which last erupted about 2 million years ago. A shield volcano is characterised by its broad, shield-like profile — unlike the steep, conical shape of stratovolcanoes, shield volcanoes have gentle slopes formed by the flow of low-viscosity basaltic lava. Over millions of years this breaks down to create extremely fertile soils, making Mt Elgon valued for its high quality arabica coffee and a major food growing area.

The base of Mt Elgon is 80km wide and features the largest mountain caldera in the world. The name "Elgon" is believed to originate from the Maasai word "Elgonyi" meaning breast, as its shape resembles that of a human breast. The park covers 1,279km² — the Ugandan section covering 1,110km² and the smaller Kenyan section 169km².

Local communities, such as the Bagisu tribe, refer to the mountain as "Masaba" — named after their founding father. The Bamasaaba are believed to be one of the oldest Bantu tribes of Eastern Uganda, originally living high up on the slopes of Mt Elgon to avoid attack from other tribes. They say that a man called Mundu, whose ancestors migrated from the Ethiopian mountains via Lake Turkana, settled in the upper reaches above the caldera where game was plentiful and caves were many. Mundu had two sons, Masaba and Kundu, and lived in a large cave at the base of Masaba Peak (Jackson's Summit) at 4,152 metres. Masaba became leader of the tribe and his descendants produced the Bamasaaba people.

The park has several trails, however the Sasa Trail is the easiest and most developed — with waterfalls, inspiring montane forests and stunning views. In September 2023, Mr John Hunwick formally from Australia signed a concession with the Uganda Wildlife Authority to develop and operate the Sasa Trail. He created a new loop trail capturing the beauty and stunning views along the Mukooka Ridge, and changed the park entrance from steep metal ladders to a new trail passing under the 61-metre Nabunyifu Falls — much easier, with incredible views as far as Mbale city and beyond. The trail also passes over the outstanding Masaba Table at 4,024 metres and directly below Masaba Summit, providing a fantastic option for hikers to climb and enjoy awesome views across the caldera.