We should be able to do that in the forum without too much difficulty. We can embed HTML into posts (just type away), change these into published pages, and even set up bespoke HTML pages to contain them if need be.
A bump of this thread. The map is still there and the s/w allows me to assign editor roles. You should be able to see the map and the 3 “features” I have added, but if you tell me your login details (I use a free openstreetmap login and suggest you do too… other options are github, bitbucket and twitter) I can add you as an editor.
The base map can be changed, OpenCycleMap is good but there are plenty of other options (B&W ones that make annotations stand out better)
Ah - found the right code (which is actually given as a link within the map under the ‘share’ link). It needs https to be put in the front of the link in order to work. I’ve made it so that it hides the menu nicely (with just the fullscreen option showing) and the size seems good.
<iframe width="100%" height="500px" frameborder="0" allowfullscreen src="https://umap.openstreetmap.fr/en/map/dunedin-betterstreetsnz_564479?scaleControl=false&miniMap=false&scrollWheelZoom=false&zoomControl=true&allowEdit=false&moreControl=true&searchControl=null&tilelayersControl=null&embedControl=null&datalayersControl=null&onLoadPanel=undefined&captionBar=false"></iframe><p><a href="//umap.openstreetmap.fr/en/map/dunedin-betterstreetsnz_564479">See full screen</a></p>