History is a great topic to write about. It becomes a reference for students or just people who would like to learn more about the ancient past. Keep working on it and take advice from these excellent hubbers. You will see your work improving in no time!
The pictures shown really grab the reader and make him want to read the history.
Yet, though you have a good chunk of history about this castle, it just starts into it.
You really don't have an introduction i.e. a summary of what this Kaunas castle is, its relevance to its country, etc.
You want to establish what the article is about and why this castle is important/worth us reading about right away. Summarize briefly the concept of your hub first.
It's also a little short so anything you can expand on would be great, and I noticed some slight grammar errors. For example, at one point (I think in one of the last few paragraphs), you spell straightened as straitened.