As someone who works in web mapping, I have to quibble with "The Google Maps of...". This is just an interactive map - it doesn't have features that particularly resemble Google Maps, particularly navigation.
A bit of work on the UI would make this a really fun and interesting tool - currently it seems to be intended for people who know a lot about the dataset already.
Navigation is supported, with travel times given for walking, ox cart, pack animal and horse. The feature is a bit hidden: you need to click the place marker at the bottom right.
A bit of work on the UI would make this a really fun and interesting tool - currently it seems to be intended for people who know a lot about the dataset already.