google.com
I haven't found a resource that easily shows you when a hotel was built so I put together the map (for a few interstate highways).
There's no reason to stay in a hotel that is old and dated when it takes a few minutes to find a new hotel.
1) I search on Google Maps for "hotels" and filter based on the hotel brand.
2) I search the reviews of the hotel for words like "new" or "old" to see what others are saying.
3) I also use Google Street View and look at previous dates of the location to make sure that even if the hotel says "new" that the hotel was not refurbished from a previous hotel.
4) I search on Google for any press releases or news reports of a new hotel built in the town.
Well, there is one reason -- if you prefer "old and dated" hotels to new ones. Lots of people do. That might be a useful option to your map: if you're tracking the age of hotels anyway, you could also produce a map catering to those who prefer the older ones.
I prefer older hotels because newer ones tend to be uncomfortable.
> If you read thousands of reviews online
Online reviews reflect a fairly narrow demographic slice.
Which is completely different, old doesn't mean not maintained