For three hundred years St Paul’s Cathedral has served as one of the enduring symbols of London, a role it richly deserves. Completed in 1708, Sir Christopher Wren’s masterwork is recognized the world over by its large dome and classical architecture.

The fame of the dome is particularly ironic since the plans, third in succession after two rejected models, didn’t call for one. Wren took advantage of a clause in the commission permitting him to make ‘ornamental’ changes.

And, in effect, the large dome – visible from several parts of London far away – is just an ornament. In the interior is a much smaller dome directly underneath and between the two a large cone-shaped structure supporting the 850-ton lantern.

Outside, astride the large dome are two towers and an extraordinary classical facade. Though it forms the entrance, the view is less familiar since photographs typically concentrate on the famous dome, which lies on the other side. The west side offers an especially good view. From here, visitors can take in the columns and the clock tower.

Whether viewing from outside or in, though, there are several outstanding features and dozens of smaller ones of interest.

One of the more popular interior features is the Whispering Gallery. As a result of the way sound waves move within an arched structure, a person can stand at one corner and whisper and be heard far away. It can be reached by a muscular climb up 259 spiral steps. Most find the effort well repaid.

Someone standing far away beneath the opposite side of an arch can still hear plainly what was said. There are often several pairs trying this at once, though. The sound is clearest if you can find a time when no one else is testing the effect.

But the main interest lies less with physics and more with art. One example is the 20-foot oak model representing Wren’s second major attempt at gaining approval for a design. Another is the large pipe organ, commissioned in 1694 and still functional.

Several other functional, yet artistic, elements are around the cathedral. One, Wren’s memorial, contains an epitaph from his son. It reads, translated from the Latin: ‘Reader, if you seek his monument, look around.’

Many other plaques, carvings, statues, and other memorials to the powerful and famous of London’s past are within the cathedral: in the south transept Admiral Nelson, in the north aisle the Duke of Wellington.

There’s also a memorial in the south choir aisle of the poet John Donne, Dean of St. Paul’s before the current building was erected. The disastrous London fire of 1666, destroyed the original. Almost ten years elapsed before construction was begun, followed by more than another 30 until completion. That gives some idea of how construction projects were carried out 300 years ago.

Undergoing a £40 million ($71 million) restoration to celebrate its 300-year anniversary, many of the building’s surfaces have been cleaned and restored. Now is an especially good time to pay a visit.

The Cathedral is easy to spot and also easy to reach via the London Underground, i.e. ‘the tube’ or subway. Exit at St Paul’s station.