Hope City does not yet exist, except as shimmering images of giant beehive towers bathed in a golden light. But Ghana is pressing ahead to build this $10bn (£6.6bn) technology city outside the capital, Accra. Designed by OBR architects, the city will consist of six towers, including a 75-floor, 270m-tall (885ft) building, the highest in Africa, where 25,000 people will live and 50,000 will work. There have been teething problems, with the site moved to a larger one at Pampram. Residents at the original location, Dunkunaa, claim the project had incurred the displeasure of the gods when the developers refused to acknowledge the chiefs and elders of the area. That could be the least of Hope City's problems, warns Professor Vanessa Watson of the University of Cape Town. She has flagged up concern not just over the Pampram project, but over other "urban fantasies" involving large-scale reconfigurations of existing cities (such as Kigali in Rwanda, and Addis Ababa in Ethiopia) or the construction of satellite cities (such as Tatu, outside Nairobi in Kenya, and Kigamboni, outside Dar es Salaam in Tanzania).