The real highlight of Barcelona's historic University Building isn't the grand façade facing Gran Via — it's what lies beyond it. Step through the main entrance and let the transition do the work: the noise of Gran Via gives way to two inner courtyards lined with elegant arched arcades, almost like the cloisters of a small monastery, and then opens out further into the Ferran Soldevila Garden tucked behind the building. This tranquil pocket of greenery, complete with a pond and lush planting, is one of the most unexpectedly peaceful spots in the entire neighbourhood — a world away from the bustle just outside. If you get the chance, it's well worth poking your head into the historic interior spaces too: the building houses an Aula Magna, a Paranimf, a library, and a sweeping grand staircase. The university does offer guided tours on request, and certain areas may be open to visitors depending on the programme and time of day, so it's worth checking ahead.

Casa Golferichs is one of those Eixample gems that rewards a second look. Unlike most buildings in the neighbourhood, it has three exposed facades — an unusual luxury in such a densely packed grid. The mix of stone and brick gives it an almost medieval character that feels wonderfully out of place against the surrounding urban blocks. Take a moment to appreciate just how striking it looks hemmed in by the city on all sides. If the cultural centre happens to be open when you visit, don't just stop at the facade — head inside. It's well worth it, and far more rewarding than a quick photo from the pavement.

Casa Vicens is one of Gaudí's earliest works, and knowing what to look for makes the visit far more rewarding. On the facade, seek out the green and white ceramic tiles decorated with plant motifs — Gaudí was essentially transplanting the garden onto the building's exterior. Notice too the Oriental-influenced ornamental turrets; this was a young architect still working in an exotic, eclectic idiom, long before the fluid organic language of Casa Batlló or the Sagrada Família took shape. Look closely at the windows and wrought-iron grilles as well — these aren't merely decorative flourishes but integral components of a unified architectural system. One practical tip: don't limit yourself to admiring the house from Carrer de les Carolines. Go inside if you possibly can. The interior reveals just how total Gaudí's vision really was — ceilings, furniture, lighting, and even ventilation were all conceived as part of a single, cohesive whole.

Stand back on the far side of Avinguda Diagonal to take in the full composition of the façade. Once you're there, notice how the entire corner of the building flows from a single continuous curved line. If you get the chance to step inside, the lobby and staircase are richly decorated and well worth a closer look.

Step inside — the real magic of this place isn't its exterior, but the way the spaces unfold around you: the staircases, the play of light, and the views that open up as you move through the building.

Casa Planells is worth a closer look as you stroll along Diagonal — just don't go out of your way for it alone. Keep an eye out for the curved balconies that appear to melt organically out of the facade, and take a moment to appreciate how cleverly the architect handled such a tight footprint.

From the street, Casa Thomas cuts a fairly modest figure, so don't let the plain exterior put you off. If you can get inside, make a point of stepping into the lobby — it's one of the most rewarding parts of the building. Look out for reptile figures woven into the décor, delicate floral motifs, and a beautifully crafted wrought-iron staircase.

Skip the exterior and head straight inside — the real magic of Walden 7 lies in its interior spaces and the dramatic views that open up between the buildings.

Casa Comalat is one of those buildings that rewards a little extra effort. Most visitors stop at the Avinguda Diagonal facade and move on, but the real surprise is around the back. Head to Carrer Rosselló and you'll discover a completely different character: wooden galleries, colourful ceramic tiles, and a green ceramic turret shaped like a harlequin's hat. Don't miss it.

Keep an eye out for the columns of pink granite, the intricate geometric and floral motifs woven through the décor, and above all the building's beautifully rounded corner, which is particularly dramatic when seen from Passeig de Gràcia. For the best experience, start at the lower end of Passeig de Gràcia to take in the façade, then walk up to the corner where it meets Carrer Gran de Gràcia — the shift in perspective is striking.