Southeast Angola is a region of in Angola.
Note that the vast national parks of Angola are almost all RINOs (reserves in name only). They were created by the Portuguese prior to independence, and have been thoroughly neglected due to 30 years of civil war, exploited and abused in pursuit of mineral and diamond wealth, and their once impressive animals hunted into oblivion. That said, they do encompass areas of significant natural beauty. Spectacularly inaccessible for physical and bureaucratic reasons, you could try to visit independently with a jeep, but it is certainly recommended to only go into these regions with an experienced tour operator. The empty southeast of the country has the largest and most remote "parks": Mucusso, Luiana, Luenge, and Longa-Mavinga. In the northeast there is the similarly undeveloped, but at least less remote Cameia National Park.
The railway line Caminho de Ferro de Benguela passes through the central parts of Eastern Angola, continuing to the border with Democratic Republic of Congo. Passenger services are sporadic, with 1-2 trains per week in each direction bet ween Kuito and Luao, the border station. The largest city along the line is Luena.