Yemen's Frontline City

Nawal Al-Maghafi reports from Yemen's front lines, where Houthi forces are posing the most serious threat in years to the city of Taiz, raising fears of a major escalation in a conflict that has endured for more than a decade. We also trace the roots of Yemen's war, exploring how the country's strategic location has drawn it into a struggle involving Saudi Arabia, Iran and the United States. Plus: BBC Mundo travels to Panama's Coiba Island, a biodiversity hotspot, to explore how a former prison colony helped preserve a rare and fragile natural world.