Titanic Belfast is the world's largest Titanic visitor attraction, a star-shaped building of shimmering steel and glass that stands on the slipway where the great ship was built. The experience covers the entire story: the construction of the ship, the voyage, the sinking, and the discovery of the wreck in 1985. It's well-designed, immersive, and genuinely moving in the final sections.
Allow at least three hours. The building's exterior, echoing the prow of a ship, is one of the most striking pieces of contemporary architecture in Ireland. The dry dock where the Titanic was fitted out is adjacent and can be walked around freely. Even if you have no particular interest in the Titanic, the Titanic Quarter itself — the regenerated former shipyard — is worth exploring for its architecture and its views of the cranes Samson and Goliath.