324 is not an area code for Southampton. Southampton's area code is (023), with eight-digit local numbers. You might be able to get a slightly more precise location if you know the first four digits of the local number after the 023 code.
The country code and area code of Ane, Netherlands is 31, (0)524.
There is no 021 area code in England. There is 020 (London) and 023 (Portsmouth and Southampton) but none in between!
The country code and area code of Barneveld, Netherlands is 31, (0)342.
The country code and area code of Doetinchem, Netherlands is 31, (0)314.
The country code and area code of Delft, Netherlands is 31, (0)15.
The country code and area code of Harderwijk, Netherlands is 31, (0)341.
In the UK, area code 023 is Portsmouth and Southampton, but there are no numbers beginning with 023 65. There are other countries with domestic numbers beginning with 02365, but you didn't provide enough information to answer your question.
The country code and area code of Grave, Netherlands is 31, (0)486.
The country code and area code of Vianen Zh, Netherlands is 31, (0)347.
The country code and area code of Bennekom, Netherlands is 31, (0)318.
The country code and area code of Maastricht, Netherlands is 31, (0)43.