The assignment asks to create a webpage with an interactive Leaflet map. So, to display some creativity, I have played around a little with icons, cyrcles, legends etc. I am not showing the tedious data preparatory code, but only the direct code that creates the map.
Mapping of a selection of public archives in Switzerland, i.e. 11 cantonal State archives out of 26 and the Swiss Federal Archives.archLatLong %>%
leaflet() %>%
addTiles() %>%
addMarkers(icon = Icon, popup = archSites) %>%
addLegend(labels = c("effective", "estimated"), colors = c("blue", "red"), title = "Running meters") %>%
addCircles(weight = 1, radius = archrm * 0.3, col = rmstat)