Yahoo paid $3.57bn for GeoCities in 1999
A service that gave many people their first taste of building and owning a web page is set to close.
Yahoo-owned GeoCities once boasted millions of users and was the third most popular destination on the web.
The free site has since fallen out of fashion with users, who have switched to social networks.
Yahoo, which acquired the site for $3.57bn (£2.17bn) in 1999 at the height of the dotcom boom, said sites would no longer be accessible from 26th October.
However, many of the pages have been archived and will still be available to view via the nonprofit Internet Archive project.
The giant digital library, which has been archiving the public web since 1996, has set up a special project to archive GeoCities before it is lost forever.
"We've collected a lot of GeoCities sites over the years - but might not have every site and every page," the Internet Archive said.
It is asking for GeoCities users to check whether their site has been archived before Yahoo pulls the plug.
"GeoCities has been an important outlet for personal expression on the web for almost 15 years," it said.
A number of firms - including Yahoo - have also tried to woo GeoCities users to move their pages to paid-for hosting services.
GeoCities started life in 1995 as Beverly Hills Internet, a small web-hosting firm.
The company allowed users to host their web pages in themed cities. For example, "WallStreet" hosted business related sites, whilst "SiliconValley" was used to host computer and technology sites.
Users, known as homesteaders, could build and host their own sites in these online spaces.
At its peak, the site had millions of users.
In April this year, Yahoo said that it was closing the site and would now focus on helping "customers build new relationships online".
When Yahoo announced the end of the site earlier this year, Rupert Goodwins, editor of the ZDNet website, said it was the end of an era.
"I think GeoCities was the first proof that you could have something really popular and still not make any money on the internet.
"It was a fascinating experiment in the pre-industrial era of the internet."