Final answer:
Lesotho and Swaziland are landlocked countries impacting their development due to limited access to maritime trade. Sudan and South Sudan feature the Nuba Mountains and Imatong Mountains respectively.
Step-by-step explanation:
Lesotho and Swaziland are the two landlocked countries contained within South Africa. Being landlocked has a significant impact on a country's development because it restricts direct access to maritime trade, which can limit economic growth and increase transportation costs. However, Lesotho benefits from its mountainous terrain as it sells water to South Africa and utilizes hydropower to generate electricity.
In terms of geographic features within Sudan and South Sudan, there are two notable mountain ranges. The first is the Nuba Mountains located in the south-central part of Sudan, which is a series of hills and massifs. The second is the Imatong Mountains located in South Sudan, which is the highest range in the country, with Mount Kinyeti as the highest peak.