Lucy Hedges heads to the city of Naples to see how staff at Pompeii are using four-legged robots and drones fitted with lasers to uncover more about what life was like in this ancient city. Cat Moh continues her trip around Britain's biggest attractions to find out how they're emerging from Covid - this week, she's at Alton Towers theme park, and adventurer Karolis Mieliauskas begins his human-powered voyage along Sri Lanka's Hamilton Canal, exploring the likely effects of climate change on this island nation.