Masterpieces at the CaixaForum

Among the first sights you see when you cross the threshold into the CaixaForum is the mural 'Splat' that conceptual artist Sol Lewit created in 2001 as commissioned by the Fundació Bancària La Caixa. 'Splat' is an onomatopoeia, a word that explains everything you see in those 18 metres of art. Nine colours expressed with irregular lines. It's a simple piece, an explosion of colour totally open to interpretation by viewers of all ages. We suggest you walk along it from one end to the other, and getting as close up to the painting as you can. Use your imagination and sense of play.

For Lewit, the idea was more important than the form, and it was typical for him to have assistants carry out the work of his sculptures and murals, following the artist's instructions. The same thing happened at the CaixaForum.

During the day it can go unnoticed, but as evening falls and it gets dark outside, a festival of lights brightens up the CaixaForum. On the exterior marquee, the ceiling of lights designed by the architect Arata Isozaki changes colours and paints the main hall. And in the middle of the entryway, like an overhead doodle, you'll see 'Spatial Environment nº 51-A', a neon structure created for the IX Triennale di Milano in 1951 by Lucio Fontana (Rosario, Argentina, 1899 – Varese, Italy, 1968).

A medium-sized room lined with lead. A cold space, with a single bulb as a point of light, that invites recollection and isolation. A place where human beings confront themselves. That is 'Hinter dem Knochen wird gezählt - Schmerzraum' ('Behind the Bone Is Counted – Pain Space'). German artists Joseph Beuys created this installation in 1983 at the Konrad Fischer gallery in Düsseldorf, and since then it's only been reinstalled once, in its current location at the CaixaForum.

The CaixaForum is a great example of how two very different, almost diametrically opposed, architectural styles can live together in perfect harmony.

After years of the structure's standing in a state of deterioration and invisibility, the Fundación Bancaria La Caixa commissioned the restoration of the former Casaramona textile factory to the Catalan architect Josep Puig i Cadafalch. It was going to be a large undertaking to be able to fulfill its new function, and Japanese architect Arata Isozaki (also behind the Palau Sant Jordi) took part as well, using the neighbouring Mies van der Rohe pavilion as inspiration.

Isozaki developed the entry and reception area of the CaixaForum on which the modernista building floats – almost literally. At the foot of the street, welcoming visitors, is the metal and glass sculpture of trees that conveys the idea of the area's natural surroundings. You are in Montjuïc, after all, so don't forget to look around at the greenery. In the open outdoor courtyard you'll find a secret garden, with a constantly running finger of water. Do you dare dip a toe in?