Imperial War Museum

The Imperial War Museum sits in what used to be the Bethlem Royal Hospital — better known as 'Bedlam,' the world's most infamous asylum. The building's dome and grand colonnades give it a stately appearance that jars beautifully with the two 15-inch naval guns flanking the entrance, barrels pointed at the sky like a warning or a memory.

Inside, the atrium is dominated by suspended aircraft, tanks, and a V-2 rocket that hangs overhead like a sword of Damocles. But the museum's real power is in the personal stories. The Holocaust Exhibition on the upper floors is one of the most devastating museum experiences in the country — not because of what it shows, but because of how carefully it lets individual voices tell the story. You'll need time afterwards.

The First World War galleries, redesigned for the centenary, recreate a section of the Somme trenches complete with sound, smell, and the claustrophobic dimensions of the real thing. The Secret War exhibition covers espionage from MI5 and MI6 with the kind of deadpan British understatement that only makes the stories more chilling. And it's all free — one of London's greatest museums that most tourists walk past on their way to the South Bank, not realising that the building behind those naval guns contains some of the most powerful storytelling in the city.