More than 14,000 streets across Britain now have an average property value of £1 million-plus, according to a website.
There are now 14,417 streets where the average property value is £1 million or over, up from 12,418 in 2016, Zoopla has found.
It identified Britain's most expensive street as Kensington Palace Gardens in London's W8 postcode area, where the average property price is £35,696,711.
Zoopla said average property values in the prestigious street are £2,569,432 less than this time last year, reflecting a cooldown in house price growth in central London.
In second place, and moving up one place from last year's ranking, is Grosvenor Crescent in the SW1X postcode of London, with an average property value of £21,984,033.
In third place, and down from second last year, is The Boltons, in the SW10 postcode of London, with an average property value of £19,858,239.
Zoopla said a huge 94.2% of streets with an average property price of £1 million and above are located in southern England.
Of the 14,417 total £1 million streets in Britain, 5,899 are in Greater London, 109 are in Scotland and 11 are in Wales.
Excluding London, Guildford in Surrey has the largest quantity of expensive streets - 204 have an average property value of £1 million or more, according to Zoopla's property "rich list".
Lawrence Hall, a spokesman for Zoopla, said: "Despite London's property market cooling over the past year, it's no surprise that the capital's most exclusive boroughs continue to dominate the list.
"This is partly thanks to some incredibly luxurious properties benefiting from unbeatable locations near the heart of the city."
More information about the locations of million-pound property hotspots can be found at Zoopla.co.uk/RichList.
Here are the 10 most expensive streets in Britain, with the average property value, according to Zoopla:
1. Kensington Palace Gardens, W8, London, £35,696,711
2. Grosvenor Crescent, SW1X, London, £21,984,033
3. The Boltons, SW10, London, £19,858,239
4. Courtenay Avenue, N6, London, £18,973,761
5. Ilchester Place, W14, London, £15,311,090
6. Compton Avenue, N6, London, £13,739,572
7. Manresa Road, SW3, London, £12,587,961
8. Cottesmore Gardens , W8, London, £11,969,745
9. Albemarle Street, W1S, London, £11,371,851
10. Chester Square, SW1V, London, £10,630,003
Here are the numbers of streets across Britain with an average property value of £1 million-plus according to Zoopla:
1. Greater London, 5,899
2. South East England, 5,278
3. East of England, 1,875
4. South West England, 532
5. North West England, 301
6. West Midlands, 194
7. Scotland, 109
8. East Midlands, 96
9. Yorkshire and the Humber, 77
10. North East England, 45
11. Wales, 11