Lviv is not just the biggest city in western Ukraine, the historic city center is also a UNESCO world heritage site. Cobblestone streets, ornate churches, and the Lviv Theater of Opera and Ballet are just some of what makes the place special. Today, people in the city are rushing to protect these cultural treasures, as they watch the Russian military’s assault on cities in the east, south and north of Ukraine. Andrew Connelly reports from Lviv.