The city of Old Dongola was capital of the Christian kingdom of Makuria between the 7th and 14th centuries and at its peak it was home to dozens of churches. The church exteriors were generally plain, but the interiors were painted in beautiful frescos – some of which are found in Khartoum's National Museum. Today little but scattered blocks, tumbledown walls and a few rows of columns remain of Old Dongola, but the sand-swept setting is sublime and you'll have the place to yourself.
A few hundred metres from the main Christian sites is a large Islamic cemetery containing several massive mud-brick, slightly pyramid-like Sufi saints' tombs. You'll need your own wheels to get here as there's no public transport.