The murals of West Belfast are unlike street art anywhere else in the UK or Ireland. These aren't aesthetic interventions, they're political documents painted on entire gable walls, covering loyalist and republican histories, commemorations, and ongoing statements. They've been here since the Troubles and they're still being added to and changed.
You can walk the Falls Road and the Shankill Road yourself, they run parallel, separated by the Peace Wall, but a local black cab tour gives you context that the murals alone can't. The drivers (usually community members from one side or the other) explain what you're looking at with a directness that no guidebook manages. It takes about an hour and costs around £20–25 per person.
The Peace Wall itself, still standing, still with gates that close at night, is one of the most sobering things you'll see in a British city. An hour in West Belfast will stay with you for much longer than most things you do here.