On Google I get the link to the download page as 3rd result, and on DuckDuckGo is the first result.
There might also be some confusion related to the fact openjdk.org only called its builds “openjdk” for version 8 and for versions 11+. Versions 7, 9 and 10 were just called “JDK” so technically there’s no such thing as “openjdk 10”.
You can download past versions of OpenJDK going back to 7 from the link I gave above.