Windows 10 ISO Files from Microsoft
Loads of sources claim the only way to get the official ISO is through the Download Tool, which is what I had previously thought as well. Now I know that their is an official direct download to the ISO files, which each also double as both Home and Pro versions, I decided I had to make it known. Above are some images of the site, but if you would like to check it out for yourself, go ahead with the link provided below.
If you want Build 10525, the latest Windows Technical Preview build, see here Winareo.