London: the beer's extortionate, the rent's a scam. But at least you can do all of this lot without reaching for your credit card...
1. See the gruesomely humorous Tippoo's Tiger at the V&A.
2. Marvel at the British Museum's Parthenon Sculptures aka Elgin Marbles (they might not be here forever).
3. Check out a Victorian computer at the Science Museum.
4. Do the 'Designer Maker User' exhibition at the Design Museum
5. Crane your neck to see Spitfires and fighter jets swoop overhead at IWM London.
6. See where our modern world began at the Faraday Museum.
7. Count the nipples in the National Gallery.
8. Peruse the Hogarths, Turners and Moores at Tate Britain.
9. See what's cooking in Tate Modern's Turbine Hall.
10. Grin back at the Laughing Cavalier at its home in the Wallace Collection.
11. Admire avant garde art at White Cube.
12. Be wowed by the neon wonderland that is God's Own Junkyard.
13. Explore what it means to be human at Wellcome Collection.
14. Take the lift to the Sky Garden for awe-inspiring London views.
15. The Garden at 120 has some pretty impressive vistas too.
16. Sign up for a free climb up the Caledonian Park clock tower.
17. Get one of the best views of St Paul's from One New Change's terrace.
18. Snap Insta-friendly wisteria pics at Hampstead's Hill Garden and Pergola.
19. Read the stories of heroic Victorians in Postman's Park.
20. Stroll around the quintessentially English gardens at Streatham Rookery.
21. Spend a rainy Sunday exploring the jungle-like Barbican Conservatory.
22. Eat your sandwiches among the bombed-out ruins of St Dunstan in the East.
23. Search for interesting names on the gravestones in one of London's 'Magnificent Seven' cemeteries.
24. Watch koi carp swim by a waterfall in Kyoto Garden.
25. Sail across the Thames on the Woolwich Ferry.
26. Use this turnstile guarding a quaint Wimbledon snickelway. No toll required.
27. Ride on the show-stopping Egyptian Escalator at Harrods.
28. Explore the Barbican from its 'pavements in the sky'.
29. Take the (very short) trip up London's only outdoor funicular railway.
Talks and lectures
30. Attend a lecture on maths, Christmas carols or pornography, courtesy of Gresham College.
31. Sign up for a fascinating afternoon talk at Guildhall Library.
32. Be a good listener at Speakers' Corner.
33. Gen up on politics, war and health at LSE.
34. Feel old by showing your kids what you used to play with, at the Museum of Childhood. [reopens 2023 as Young V&A]
35. Explore south London's version of Jurassic Park, aka the Crystal Palace Dinosaurs.
36. Visit the children's-only park and playground at Coram's Fields (as an accompanying adult, you can go in).
37. Get lost in the winding cobbled alleyways of Sailortown.
38. Sign up your little 'un for a Storyplay workshop.
39. Watch them captain an ice-breaker at AHOY! children's gallery.
40. Keep them occupied for hours in the Granary Square fountains.
41. Delve into the remains of a London amphitheatre.
42. Explore a long lost Roman temple secreted below the Bloomberg building.
43. Take a stroll beneath the Thames via the Greenwich Foot Tunnel.
44. Check out the latest graffiti masterpieces in Leake Street Arches.
Religion and faith
45. Experience a Hindu 'Aarti' ceremony at Neasden Temple.
46. Sing hymns at Westminster Abbey.
47. Attend a service at the beautiful Bevis Marks synagogue.
48. Explore one of Europe's largest Sikh temples (and eat some amazing food while you're there).
49. Take a tour of the East London Mosque.
50. Be bedazzled by the gilded ceiling of Fitzrovia Chapel.
Quintessentially London experiences
51. Hang outside Buckingham Palace one afternoon for Changing the Guard.
52. Make a call to the Westminster red phone box and see who answers.
53. See justice in action at the Old Bailey.
54. Pay homage to the mystical London Stone.
55. Lift a solid gold bar at the former Bank of England.
Self guided tours
56. Tick off Londonist's collection of Weekend Walks.
57. Go in search of ghost signs (maybe using this superb book as a guide).
58. Explore the West End with Ian McKellen.
59. Walk The Line, spotting zany sculptures across North Greenwich and east London.
60. Walk around the whole of Greater London, via the London LOOP (not in one go — it's 150 miles).
61. Go in search of chewing gum art on Millennium Bridge.
62. Bathe in some Bach at a lunchtime concert at LSO St Luke's.
63. Treat your ears to 45 minutes of classical music at St Martin-in-the-Fields.
64. Play Elton John's piano at St Pancras International.
65. Dance on a clown's grave at Joseph Grimaldi Park. (It's a musical grave.)
66. Play with the wonderfully loopy Lullaby Factory at Great Ormond Street Hospital.
67. Enjoy a bitesized chunk of opera at the Royal Opera House.
68. Listen to students sing in the Dulwich Picture Gallery's Christ's Chapel.
69. Spend your lunch break listening to live classical music at Lauderdale House.
70. Catch free comedy in Angel (but put something in the bucket if you can afford to).
71. Take a dance class at Bar Salsa!
72. Enjoy some open mic spoken word in Hackney.
73. Be in the audience on Graham Norton's popular chat show.
74. Discover the next big music artist at the Old Blue Last.
75. Pretend you can afford that candelabra at London Silver Vaults.
76. Admire the mock Tudor beauty of Liberty department store.
77. Snaffle a few cheeky samples at Borough Market.
78. Smell the blooms at Columbia Road Flower Market.
79. Watch people haggle at the world's largest antique market in Notting Hill.
80. See what's going under the hammer at a police auction.
Libraries and archives
81. Do a spot of research in the British Library's Reading Rooms.
82. Pore over 1,000 years of history at Kew's National Archives.
83. Discover amazing stories at the Black Cultural Archives.
84. Explore the the world's oldest collection of material on the Nazi era at Wiener Library.
85. Leaf through archives on costume, advertising and architecture at the Rotherhithe Picture Research Library.
Sport and exercise
86. Get up at a decent time on a Saturday, and do a Parkrun.
87. Sign up for a free class at Sweaty Betty.
88. Watch boarders take on quarterpipes, ledges and flat banks at Stockwell Skatepark.
89. Play giant chess in Holland Park or Victoria Embankment Gardens.
Nature and animals
90. Feeed the biiiiirds parakeets in Kensington Gardens.
91. Spot deer in Richmond Park.
92. Get a taste of rural life at one of the city's many urban farms.
93. Count moles in a jar at the Grant Museum.
94. Say hello to the overstuffed walrus and his friends at the Horniman Museum.
95. Have a four-tonne blue whale hover above you at Natural History Museum.
On the Thames
96. Go mudlarking (or simply visit a Thames beach at low tide — Bankside is particularly good).
97. Listen to a 1,000-year-long piece of music in a lighthouse.
98. Help clean up the foreshore, with Thames21.
99. Watch Tower Bridge open up for a big ship — it does it more often than you might think.
100. Help homeless people by volunteering your time at a charity like Crisis, St Mungo's or Centrepoint.
101. Get green-fingered in a community garden.
102. Discover countless other volunteering opportunities through Team London.