Nearly 700 species of flightless mammal could be barred entry to cooler habitats due to national borders by 2070.
The fault lines between highly segregated neighbourhoods have been linked to higher crime rates and mental health issues.
The pastiche-style poster art ubiquitous in Egyptian houses and businesses reveals how locals imagine far-off landscapes, idealise nature and define beauty.
What do border walls cost? And do they work?
The logic behind building a wall is centuries old. But can concrete solve the complex problems the U.S. is facing today?
Donald Trump, if he takes the US presidency, will immediately start building a wall between Mexico and the US. What lessons can he take from that celebrated wall-builder, Chairman Mao?
In response to high levels of crime, South Africans have turned their homes into fortresses, seeking security behind high walls. But doing so might be counter-productive.