When in Europe — especially, in my experience, in Eastern Europe — it isn’t uncommon to see this or that glorious monument with an inscription on it that has this interesting combination of differently-sized capital letters. The above photo is of the base of a monument to the Blessed Mother in Bratislava, Slovakia; I have seen these types of inscriptions in Austria, Czech Republic, Slovakia, Hungary, and other places. Sometimes it’s just a question of capital letters of differing sizes; sometimes, like in the above example, there are different colors to set off certain letters.
Fr. Hunwicke has a great post about this very thing today. This type of inscription is called a chronogram. While it is pretty cool-looking and, in my opinion, even if it didn’t mean anything in particular, would be a neat way to do inscriptions — yet, it turns out that it does, in fact, mean something. The larger letters are Roman numerals and, when added up, often represent the year the monument was placed or some other significant date. Read Fr. Hunwicke’s post for more complete information on this type of inscription.
Of course, then the challenge is knowing what the Latin says… but even if you can’t read Latin, you can figure out the date/year and perhaps, with the help of the internet, learn more about it that way!