The cartopy.feature.NaturalEarthFeature class of cartopy looks like a very convenient way to add high quality map features, but I haven't been able to figure out what values are allowed for the name parameter at class initialization. The documentation indicates it needs to be a valid dataset name from www.naturalearthdata.com, but the dataset information there does not give clear indication of the datasets' names.
I have tried the obvious such as 'natural-earth-i-with-shaded-relief' (or variant 'natural_earth_i_with_shaded_relief') and other such guesses, but none of my guesses worked. The only names that don't drop a 404 on me are 'land' and 'ocean' under the 'physical' category -- but even then, although the code runs it doesn't render anything for those features. I am expecting some sort of basic land or ocean shading at the very least. Ideally I would like to add physical shaded relief as a backdrop to my data overlay.