Within the revitalised 1880s Palau de Mar, this excellent museum travels from the Stone Age through to the arrival of Modernisme in Catalonia and the Spanish Civil War (touching heavily on the cultural and political repression felt across Catalonia postwar) and into the 21st century. It's a busy multimedia hotchpotch of dioramas, artefacts, videos, models, documents and interactive bits: all up, a thoroughly entertaining exploration of 2000 years of Catalan history. Signage is in Catalan, Spanish and English.
You'll see how the Romans lived, listen to Arab poetry from the time when the city was under Muslim rule, peer into the dwelling of a medieval family in the Pyrenees, try to mount a knight’s horse or lift a suit of armour, and learn all about the Greek-then-Roman port of Empúries (on today's Costa Brava).
Afterwards, head upstairs to the first-rate rooftop restaurant 1881 and its attached cafe-bar. The temporary exhibitions (€4) are often as interesting as the permanent display.