The Fòrum and Diagonal Mar: the 21st-century edge
A blue cantilevered triangle, a solar canopy over the sea, and Miralles' water park behind it. This is a Claude-drafted route awaiting the editor's walk.

1. Edifici Fòrum
Start under the great blue triangle — Herzog & de Meuron's convention building, a flat slab cantilevered out over open plaza on impossibly few supports. The deep-blue rough-rendered underside is the show; walk right beneath it and look up.

2. Museu Blau
The natural-history museum shares the slab — fossils, minerals, a whale skeleton, all under one roof. Good on a hot afternoon when you want shade and air-conditioning. The 'Planeta Vida' permanent show is the one to see.

3. The photovoltaic canopy
Walk towards the water and the enormous tilted solar pergola comes into view — a single vast panel on a stalk, angled at the sun, throwing shade on the esplanade below. It looks like it landed here. Stand in its shadow for the scale.

4. The bathing zone
Past the canopy, the Fòrum's swimming area — not a beach but a sheltered concrete-edged sea pool where the city swims off the rocks in summer. You don't have to get in; the steps down to the water are a fine place to sit with the harbour traffic.

5. Parc de Diagonal Mar
Turn inland to Enric Miralles' park — looping white pergolas hung with terracotta planters, ponds and channels threading between them. It's a water park in the literal sense, all curves and reflection. Follow the water; it leads you through.

6. Rambla de Prim
The wide tree-lined avenue back towards the metro, cutting through the newest, most planned stretch of the city. After Miralles' curves it feels almost severe — which is the point of this whole walk, the old harbour edge rewritten in straight lines and engineering.

The Fòrum and Diagonal Mar: the 21st-century edge