Although not on everyone's priority list, for me this is one of Barcelona's most interesting museums. In part, that's because it's easy to forget when wandering around Barcelona that it's actually a maritime city. And partly, because the building is for once as interesting as its contents.

It's housed in the former Royal Shipyards, a covered ship-building dock built between 1283 and 1328. Comprising essentially a series of magnificent and spacious gothic vaults, it's one of the largest and best preserved mediaeval secular buildings in Europe.

The collections begin with a series of ships, boats and models, the highlight being the replica of a 16th-century royal galley, covering the whole of Spain's maritime past. There's a good exhibition of maps and cartography, documenting the discovery of the New World and, as you'd expect, lots on Spain's colonial and trading history.

Less expected is the unique collection of votive paintings offered by sailors before their seafaring adventures to various maritime-inclined saints. There are also extensive collections of models and maritime paintings.

It has the usual services you'd expect of a large museum (cafe, shop, audio-guides and activities for children), but my only gripe is the fearsomely complicated ticket pricing system, with all sorts of discounts and optional extras (including a visit to a ship in the harbour, and a harbour tour). So visit the web-site before you go and plan ahead! Allow half a day to do it all justice.