Server side image maps are a fun one also: https://rickcarlino.com/2021/what-were-server-side-image-map...
this is back when every single byte mattered and saving a few MB was the difference between a good user experience and a bad one.
for those that never used this, you would do something like
<img src="funnycats.jpg" usemap="#funnycats-map">
<!-- the map defines clickable zones --> <map name="funnycats-map"> <shape="rect" coords="34,44,270,350" href="cats.html"> </map>
most ppl used something like Dreamweaver but bad-asses would do their own coordinates.
Why could you not have defined elements overlayed using high z index that were clickable, like invisible divs?
Client side image maps and the script element were (AFAICT) both introduced in Netscape 2.
Even when scripting was introduced, you didn't necessarily have the ability to move elements around freely on the page. I think (but I'm not certain) that it wasn't until Netscape 4 era that you had enough layout primitives to implement the multi-layer positioning approach to custom clickable areas.
<div class="image-map">
<img src="funnycats.jpg">
<a
href="cats.html"
style="position:absolute; background: transparent; left: 8.5%; top: 12.5%; width: 59%; height: 87%;"
></a>
</div>