Found 98 feet (30 metres) above the cathedral’s floor, the Whispering Gallery at London’s iconic St Paul’s Cathedral is an architectural marvel.

As with other “whispering galleries” found around the world, its construction is such that something whispered into the wall on one side of the gallery, which runs around the interior of the cathedral’s inner dome (part of the first ever ‘triple dome’), can be heard on the other side of the gallery, around 100 feet (30 metres) away.

The dome (pictured right), the design of which draws inspiration from that of St Peter’s Basilica in Vatican City, was constructed to the designs of Sir Christopher Wren. The cathedral, including the dome, was essentially completed in 1708.

As well as giving views down into the cathedral, the Whispering Gallery – a relatively easy climb of only 257 steps – also provides a close-up view of murals painted on the dome’s inner surface by Sir James Thornhill. Painted between 1715 and 1719, these depict images from St Paul’s life.

Two further galleries on the dome are also publicly accessible – the Stone Gallery, which stands 173 feet (53.4 metres) above the cathedral floor, and the Golden Gallery, which stands 280 feet (85.4 metres) above the cathedral floor and offers stunning views of the city as well as southward over the Thames. But be prepared for a long climb – 528 steps – up what are in places narrow, winding staircases.

The current ball and cross on top of the dome date from 1821 (these replaced those which had first topped the cathedral). Together they stand 23 feet (seven metres) high and weigh seven tonnes.

WHERE: St Paul’s Cathedral, St Paul’s Churchyard (nearest tube station is St Paul’s); WHEN: The galleries are open from 9.30am to 4.15pm, Monday to Saturday (small children must be accompanied by an adult)/Cathedral is open from 8.30am;  COST: £14.50 an adult/£13.50 concessions and students/£5.50 a child (6-18 years)/£34.50 a family of four; WEBSITE: www.stpauls.co.uk