Inevitably, every visitor to London forms a relationship with the Tube.
In other cities, underground railways are practical, no-nonsense ways to get around town quickly.
But the London Underground has always seemed more than that. Its distinctive logo, its iconic route map, its many stations with curious names, and the strange unearthliness of its deep-level platforms, give it a personality all its own.
Basically, the Tube is a London character, taking its place alongside policemen with domed helmets and the last few Cockneys running jellied eel stalls in the East End.
It opened for business in 1863, and now has 270 stations along 400km of track, with over 4 million journeys made each day.
You don't get this big – or this old – without developing some eccentricities and secrets along the way. Here are some quirks to look out for on your next trip below London.
23-24 Leinster Gardens: The fake houses
When the Underground extended into the posh suburbs south of Paddington in the late 1860s, the railway engineers had a problem. The inhabitants of Bayswater were wary of railways spoiling their pleasant streets, and an open-air section was needed to let trains vent their steam.
The solution was to demolish two houses in quiet Leinster Gardens, build the railway line through an open cut below, then replace the buildings with facades.
Nowadays these mock houses sit between two hotels, the Henry VIII and the Blakemore. They're very convincing, fitting seamlessly into the tree-lined street's row of elegant white buildings with Grecian columns and balustrades.
The fake frontages were featured recently in the BBC's Sherlock TV series; so the secret is out, at least for some.
When I ask the desk clerk at the Hotel Henry VIII about the facades, he says "Someone has already checked into Room 501 because of that." From that room, apparently, you can see down into the railway cavity.
Nearest station: Queensway.
St Mary Woolnoth's Crypt: Walking through a crypt
Next to Bank station on King William Street is St Mary Woolnoth. An imposing Georgian church with two turrets, it was designed by the renowned architect Nicholas Hawksmoor and opened in 1727.
It nearly didn't survive the coming of the Underground in 1900, when the railway company building the Northern Line wanted to demolish the church in order to build their station. A public outcry saved it from destruction. Instead, the company bought the church crypt, whose contents were removed for reburial.
The church was then supported by steel beams while a ticket hall, staircase and lift shaft were constructed beneath it. This is why St Mary Woolnoth is one of the few old London churches without a crypt. Though if you head toward the Docklands Light Railway platforms, you'll be walking right through it.
Nearest station: Bank.
Brunel Museum: A cavern for concerts
In 1843, the Thames Tunnel opened between Wapping and Rotherhithe in East London.
The brainchild of engineer Marc Brunel and his son Isambard Kingdom Brunel, it had begun in 1825 with the sinking of a huge shaft. A team of men then slowly tunnelled under the Thames.
Disasters were frequent, with work being interrupted by floods, sewage, methane gas and fires. The worst flood, in 1828, killed six men. Finally the tunnel opened, but without ramps for road traffic. Fitted with stairways, it became a tourist attraction, and a haunt for prostitutes and pickpockets.
Nowadays it's a railway tunnel for the Overground, whose routes are shown on the Underground map in orange.
On the south bank, within an old engine house, is the Brunel Museum. Its great highlight is the former entrance shaft, leading down to a cavernous space which is used for occasional concerts. You can see it on one of the museum's regular guided tours.
Nearest station: Rotherhithe.
Stairway to Heaven: A tragic trip
On the evening of 3 March 1943, East Enders were hurrying into Bethnal Green station to shelter from a German bombing raid.
Suddenly, a woman holding a baby tripped at the bottom of a staircase. Some 300 people followed her, becoming caught in a huge tangle of bodies; 173 of them died. It was Britain's biggest civilian disaster during World War II.
Now a trust is building a memorial to the tragedy, in the park next to the ill-fated Tube entrance. When complete, the Stairway to Heaven will support an inverted staircase, with 173 pinpoints of light to represent the victims.
With fundraising ongoing, so far only the base has been installed. Even so, it's a harmonious structure with plaques describing the tragic events, including quotes from survivors.
Looking at the long list of victims, it's heart-rending to see so many who were from the same families; and deeply moving to see them remembered.
Nearest station: Bethnal Green.
Ghost stations: Call for your mummy
For bonus points, seek out the remaining surface buildings of closed "ghost stations". You'll recognise the former Aldwych station on The Strand near Australia House by its oxblood tiles and the sign with its original name: Strand Station. This intact dead-end station is often used as a filming location.
Another ghost station is Down Street. Between Green Park and Hyde Park Corner stations, it was used as a bombproof base by Prime Minister Winston Churchill during World War II. It later starred in the 1996 BBC fantasy TV series Neverwhere, for which a dinner was filmed on the remnant station platform as trains rushed by a few metres away.
Sadly, the surface building of the former British Museum station was demolished in 1989. However, stay alert as you pass between Holborn and Tottenham Court Road on the Central line, as the station was rumoured to be haunted by an Egyptian mummy. You never know what you might see…
Tim Richards travelled at his own expense. His fantasy novel, Mind the Gap, features the London Underground and is available as an ebook published by Harper Collins.
Qantas (131313, qantas.com.au) flies from Sydney and Melbourne to London.
The Athenaeum, 116 Piccadilly, Mayfair, is an attractive upmarket option right next to Down Street ghost station. Rooms from £300 per night. See athenaeumhotel.com.
Radisson Blu Edwardian Grafton Hotel, 130 Tottenham Court Rd, Fitzrovia, offers accommodation with a lively contemporary theme. Rooms from £140 per night. See radissonblu-edwardian.com.