Lunaria. The name makes one think of something related to the moon, maybe a kingdom that has a special connection to lunar cycles, like its magic being stronger during a full moon or its architecture being built to honor the moon.
Avalon. It has a mysterious and magical feel, often associated with Arthurian legends. It gives the impression of a place full of wonder and adventure.
One way is to combine words from different languages. For example, use a Latin root word like 'Regnum' which means kingdom and combine it with an English descriptive word like 'Frost' to get 'Regnum Frost'.
Avalon. It has a mysterious and magical feel, often associated with Arthurian legends. It gives the impression of a place full of enchantment and heroic deeds.
For a fantasy story, you might consider 'Whisperwind Kingdom'. It gives the feeling of a place where the wind seems to carry secrets. 'Moonbeam Realm' is also quite unique, making one think of a place that is somehow connected to the moon's light. Then there's 'Sunspark Dominion', which could be a place full of bright, warm energy, perhaps where the sun has a special significance.
You can combine words related to nature, like 'Mysticwood Kingdom' or 'Crystalpeak Realm'. Also, think about using archaic words, for example, 'Avalon' or 'Camelot' are classic and can be a great inspiration. Another way is to play with emotions or qualities, such as 'Valor Kingdom' for a brave one.