Jake,
In a simple html page an anchor is defined and links to the anchor moves you to that part of the page, such as a heading. They are a kind of internal link.
Now if you stop to think about it tiddlywiki has a lot of features about internal links, it open tiddlers, and executes buttons and a lot more, all in the same page.
As a result the anchor method is used in the way tiddlywikis page works and the standard simple anchor is not easily available, however people have found tricks, workarounds and even better alternative solutions. The answer is not strait forward.
However as it often the case here is if you try and ask what you want from tiddlywiki, functionally, rather than ask a question with a partial solution eg an anchor is a "method to an end" not "an end in itself" like try this "Is there a way to get links to jump to a heading in a long tiddler?" you are far more likely to get the answer you seek.
Regards
Tony