A leafy north London cul-de-sac littered with large detached properties, it may sound like thousands of streets scattered across Britain. But there's something special about Courtenay Avenue, N6; with an average house price of £6,803,900, it is the priciest place in which to buy a property not just in London, but nationwide. It beat last year's most expensive street by more than £1m; in 2007 top of the league was Kensington Square in W8, where the average home cost £5,534,480. Kensington Square has dropped to 16th place in this year's mouseprice.net report analysing Land Registry data. Perhaps unsurprisingly, 15 of London's top 20 most expensive streets are located in The Royal Borough of Kensington and Chelsea.

Property prices on the 20 most expensive streets in London:

1 Courtenay Avenue, N6: average property value - £6,803,900

2 Chelsea Square, SW3: average property value - £6,440,600

3 Manresa Road, SW3: average property value - £6,193,300

4 Ilchester Place, W14: average property value - £5,840,200

5 Gilston Road, SW10: average property value - £5,584,100

6 Carlyle Square, SW3 : average property value - £5,581,300

7 Eldon Road, W8: average property value - £5,512,000

8 The Vale, SW3: average property value - £5,439,400

9 Carlton Gardens SW1Y: average property value - £5,285,300

10 Albert Place W8: average property value - £5,255,500

11 Ingram Avenue, NW11: average property value - £5,164,700

12 Victoria Road, W8: average property value - £5,092,200

13 Thornwood Gardens, W8 : average property value - £5,012,400

14 Highbury Road, SW19: average property value - £4,935,200

15 Mulberry Walk, SW3: average property value - £4,873,900

16 Kensington Square, W8: average property value - £4,827,900

17 Winnington Road, N2: average property value - £4,732,200

18 Priory Walk, SW10: average property value - £4,694,700

19 Douro Place, W8: average property value - £4,678,000

20 Cottesmore Gardens, W8: average property value - £4,656,500

Source: mouseprice.net

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