Less impressive externally than nearby Neuschwanstein, this castle was actually lived in by the royal family (include King Ludwig II before he became the “mad king”) and thus has complete interiors. Tour this as well as Neuschwanstein. The castle is bright yellow and built in a neo-Gothic style on top of 12th century ruins from the Schwangau knights. It hosts all original furniture. It’s a very swan-heavy castle, look for the swan painted frescos. Wagner used to play the piano you see for King Ludwig in his early years.
Reserved tickets must be picked up an hour and a half in advance of your reservation. You could visit the museum of the Bavarian Kings while waiting. The website says that on 2020 they will be trialing being able to actually buy the tickets (not just reserve them) online and being able to print at home or have on your phone. This sounds like a much better system – but check and see.
If you decide to just get in line then the line may be quite long (and in summer sometimes they sell out). Our advice is to get there earlier and miss the later crowds.