On the rocky coast of Calpe in Alicante stands one of Spain's most photographed buildings: La Muralla Roja, a scarlet, fortress-like apartment complex designed by architect Ricardo Bofill and completed in 1973. Inspired by the kasbahs of North Africa, it looks like a Cubist citadel from a distance — but up close it's a lived-in home, with plants on balconies, neighbours chatting in tangled stairwells and a quiet pool on the roof.

The building's layout is based on a Greek cross, and its interiors shift through striking shades of red, orange, blue and violet, chosen to play off the deep blue of the Mediterranean and the pale, dry landscape around it. Climbing the winding pink staircases, with slivers of sky cutting through the geometry, is the closest most of us will get to walking around inside a painting.

Here's the catch: La Muralla Roja is a private residential building with around 50 apartments, and there are no walk-in tours or ticketed visits. Viewing is exterior only, from public roads, and it's free — plan on 15 to 30 minutes for photos. The better option for devoted fans is to rent an apartment directly from a resident, which is occasionally possible for a few nights or even a few weeks. Book well ahead; demand far outstrips supply.

If you're making the trip, consider pairing it with a walking tour of Bofill's other work in the area, including the Xanadu apartment complex nearby — an olive-green, angular building that resembles a pagoda sliced apart and reassembled. Calpe itself is a proper seaside town with beaches, so you can admire the building from the shore and then do normal holiday things.

One etiquette note worth taking seriously: this is people's home, not a film set. Spanish residents here are protective of their privacy, and overshooting into stairwells or terraces without permission can earn you a firm talking-to. Shoot from public viewpoints, keep noise down, and if you've scored a rental, treat the neighbours as neighbours.

Why bother for a single building? Because few places deliver this much visual payoff for so little effort. It's free to see, accessible year-round, and photogenic at almost every hour — though spring and autumn bring softer light and thinner crowds than the summer high season. For design lovers, Instagram planners and anyone road-tripping the Costa Blanca between Alicante and Valencia, it's an easy, memorable detour.

Story via Unusual Places.