When I imagine a castle I also tend to think of something similar to the first image which is often the prime example of a medieval castle castle (Bodiam castle?) For me places like Neuschwanstein Castle only come up if it's described as a Palace (which it technically is) or described in alot of...
Hms Warpsite assuming it's a fantasy world. Warspite had real life plot armour so should be invincible!
If its a more modern other world probably a type 45 destroyer.