Metropolitan Cathedral of Saint Sebastian

The Catedral Metropolitana de Sao Sebastiao is the building that surprises everyone who walks into it. From the outside, on Avenida Chile at the edge of Lapa, it is a huge, truncated cone of grey concrete, stepped and latticed, that has divided opinion since it was built and is sometimes compared to a Mayan pyramid or a beehive. Inside, the effect is completely different. The space is a single, enormous circular hall with no columns, and four great bands of stained glass rise from the floor to the cross-shaped skylight at the top of the cone, filling the interior with coloured light that shifts through the day from deep blue and green to red and gold. The cathedral is dedicated to Saint Sebastian, the patron saint of the city, and was designed by the architect Edgar de Oliveira da Fonseca and built between the 1960s and the 1970s, replacing the old colonial cathedral nearby as the seat of the Archdiocese of Rio. Riotur's figures give a sense of its scale: it stands 75 metres high on the outside and 64 inside, measures 106 metres across at its base, and can hold around 20,000 people standing or 5,000 seated. Beneath the high altar lies a crypt, and the basement holds the Archdiocesan Archive, a collection of documents on the social, political and religious history of the city. The cathedral remains a working church with regular services, and its vast interior is used for major celebrations of the archdiocese. Its location makes it easy to combine with other sights: the Lapa Arches and the Selaron Steps are a few minutes away, the Theatro Municipal and Cinelandia are a short walk north, and the Carioca station, where the Santa Teresa tram departs, is close by. Entry is free, and a visit takes half an hour or so, though photographers can spend much longer watching the light change.

How to visit: go in the late morning or early afternoon on a sunny day, when the light through the stained glass is at its most intense; stand in the centre of the floor and look up to the cross of light at the top. Dress modestly, keep your voice down and avoid visiting during mass if you want to wander freely, though attending a service is a moving experience in a space of this size. Photography without flash is generally fine outside services.

Safety and access: the cathedral sits on a busy avenue in the centre, near the Petrobras headquarters and the Lapa Arches. The area is fine on weekday daytimes but quieter and less comfortable at weekends and after dark, so plan a daytime visit and arrive by ride-hailing car, metro (Carioca station) or the VLT light rail. Keep valuables out of sight on the walk to Lapa.

Who it suits: architecture lovers, photographers and anyone who enjoys a building that defies expectations. Even visitors who dislike the exterior usually leave impressed by the interior. Children like the scale and the colours; it is short enough to fit into any day in the centre.