From Hentschel
/* Neuschwanstein Castle */
==== Neuschwanstein Castle ====
One of the destinations that are somewhat hard to reach by public transportation is the Neuschwanstein castle, but it's only about 90 minutes by car. It's the castle that inspired Walt Disney for his Disney Castle. The place can get quite busy by 10 or 11 AM, so if you get going early, you have a chance of missing long lines and a large crowd. Just do the tour, walk up to the bridge with its magnificent view and "get out" before the crowd hits the place.
Also, it may make sense to buy the tickets for the castle ahead of time, if you know when you're gonna be there. Beware that if you get there late, you won't be offered another spot later, unless someone else doesn't show up. You cannot reserve tickets online for the same day. The website is: https://www.hohenschwangau.de/430.html
There are two castles there, Neuschwanstein (the famous one) and Hohenschwangau (the not so famous one). If your pressed for time, I'd rather skip the 2nd one, and move on to the next one:
==== Linderhof Palace ====