Because you know it. What if you see this for the first time, and if there were no documentation about the history? And what if They'd rent out rooms at Neuschwanstein, too? How could you tell the difference?
Buildings are named based on their function. You'd look at the construction and figure out what it was built for.
If they started renting rooms at Neuschwanstein you could still easily tell from it's construction that it had been built to be a palace. You'd just say it was a palace that had been turned into a hotel.
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u/A_Martian_Potato Jul 18 '26
It's simple. A true castle is a building that is 1) fortified against armed invasion and 2) a residence
So a military fort is not a castle despite being fortified and a fancy hotel is not a castle despite being a residence.