>> if you want to reach anything ... you have to build 100 castles
Funny story:
I started playing on one server not long after Big Point launched the game. At that time, there were no gems, no Deeds of Conquest, no Baldur's Fortresses (golden castles). There existed only regular castles. The resources needed for construction wagons increased exponentially, to the point that they became effectively impossible to pay for, once you had a couple of dozen castles.
Many new players joined for a day or two, created some low point castles, and then lost interest. After a couple of weeks, those tiny castles dotting the map would turn grey, and then a week or two later disappear off the map.
The active players ignored the tiny grey castles, in favor of using construction wagons (choosing their preferred locations) or else conquering larger already built-up castles. Nobody wanted to spend the time to build up some tiny castle, probably created by a novice on a bad square to start with.
But I and one other player looked at the cost of construction wagons and realized that the only way to get a lot of castles was to conquer them, that there would be a lot of competition for the larger castles, and that if you used a construction wagon, you'd have to build them up anyway, with the disadvantage of spending a fortune in resources, better used for troop recruitment.
So the two of us started conquering every small grey castle we could find. It was a race. Building them up was a time-consuming chore. When he had about 150 castles and I had over 100, we had the highest point totals, and other players began to take notice.
So did Big Point. They totally panicked, thinking that we would consume the entire map, all 100 continents, not leaving any squares free for new players to join.
So Big Point initiated a 20 castle per person limit, forcing players to choose which 20 they wanted to keep, and demolished all the rest. That was a lot of work down the toilet. Not all of the 100+ castles I had were built up, but I had way more than 20 good castles, at least 40, probably 60.
In the years after that, they introduced gems, Deeds of Conquest, and the Baldur's Fortresses with the aim to give the players a chance to obtain more than 20 castles again.
The result, as you can see now, is a handful of dominant players with hundreds of Baldur's Fortresses
Even with that, and after combining several servers worth of castles onto one world, the space still didn't run out either.
I only played on one server, so when other players who did play on several servers got to take all their castles from multiple servers onto one world when Bitmeup took over, I had comparatively few castles, only 72. I didn't choose a great location, and I ended up demolishing almost all of those to prevent them from being conquered. I lost a couple of billion troops in the process, and the attackers never ran out of troops. That situation was subsequently rectified, but the damage was done, which is why I'm happy to play now with just 6 10 castles. (I just built 4 more in order to be able to have 10 knights.)
So I was the second person on my original server to have over 100 castles, I don't know about the other servers.