Hertfordshire's most popular postcodes have been revealed – and Watford has come out on top.

Purplebricks based its rankings on the number of viewings seen on its website during March, with three WD postcodes and two ALs making up the top five.

We found out why they're so popular...

1. WD25

Garston, Leavesden, Aldenham, Letchmore Heath

With the M1 running through the centre of the postcode and popular attractions such as Leavesden's Warner Bros. Studio Tour and Garston's Vue cinema, WD25 is packed with selling points.

There's another side to the postcode in the form of sleepy Aldenham and little Letchmore Heath, which balance out the buzz with their sleepy, affluent village vibe.

Rightmove recorded an average sale price in WD25 over the last year of £450,917.

2. WD18

West Watford, Holywell

Taking in the southern tip of Cassiobury Park, Watford tube station and Watford General Hospital, the WD18 postcode covers off several of the town's major landmarks.

According to Rightmove, the average sale price in the postcode over the last year was a relatively affordable £363,822, with terraced houses making up the majority of the transactions.

3. AL4

St Albans, Wheathampstead, Sandridge, Colney Heath, Tyttenhanger, Gustard Wood

It's easy to understand the appeal of AL4, which is home to some of Hertfordshire's prettiest villages, including Wheathampstead and Sandridge.

The St Albans part of the postcode is packed with outstanding schools, including Sandringham and Beaumont, while fabulous green spaces include Heartwood Forest and Nomansland Common.

The average sale price over the last year was £630,566.

4. WD19

Oxhey, South Oxhey, Carpenders Park

Immediately south of WD18 is WD19, which includes the desirable Oxhey village. With an average price over the last year of £466,274, it's more expensive than its neighbour.

Bushey and Carpenders Park tube stations are within the postcode, as is Oxhey Activity Park, with its skate park, cafe and play area.

5. AL7

Welwyn Garden City

AL7 covers the eastern half of Welwyn Garden City, including Panshanger, Peartree and the George V playing fields.

According to Rightmove, the area had an average sale price of £362,888 over the last year – noticeably more affordable than the other half of town, AL8, which recorded a more premium price of £525,328.