The Katse dam is a seriously impressive piece of design. Standing at 185m tall, it is Africa’s second largest curved dam. Completed in 1996, it forms part of the Lesotho Highlands Water Project, which was the result of a deal signed between the governments of Lesotho and apartheid South Africa a decade earlier. The country might be entirely surrounded by its much larger neighbour, but it has something parts of South Africa lack – a regular supply of water. The government says Lesotho receives $200m a year from South Africa for the water – more than double what the country used to get after the agreement was renegotiated earlier this year.