Not big, indeed. Can be classified as small. It is four steps in circumference.... An outstanding traveller (an outstanding liar as well, like many travellers a few centuries ago) renowned in the world where people used to write from the right to the left, and not famous at all in the world where people used to write from the left to the right, measured sizes of castles with steps, but he never mentioned what those steps were like, nor whether the legs were long or short. Four comparing to one thousand (the castle defending a strait in a sea elsewhere was just one thousand nobody-knows-what steps in circumference – I wonder: are there any straits in Liberland?) sounds really shocking, even if the steps were unnaturally long, so long that making them would cause lack of balance, unless the legs belonged to a giant which is obviously unlikely..... However one thing should be modified. The circumference of Sand Castle should not be measured with leg steps, but with finger steps, so with steps made by index and middle fingers. Then the castle will be almost fifty steps in circumference, which is not shocking number, but still confirming the smallness of this edifice.
Yes, this castle is small and compact.
Square.
With no bulwarks and ramparts.
No bastions.
There is only one projection which emphasizes the compactness of the castle's body. This projection itself is compact, has no projections (so, there are no secondary projections – taking in account the hierarchy of the whole castle). It is short and ends with a round tower. A kind of barbican.
The walls are smooth. Nothing is projecting. Boring walls, but not easy to climb. Should be slippery, but the surface is rough. It's not good.
Boring? No. Of course not. Let's look at the towers. We already know one of them – the one which is more a barbican than a tower, something between a tower and barbican (as usually everything depends on definition). And this one is located where it is supposed to be located: in the corner, or, more precisely, in the corner area. The second tower, the one in the opposite corner (opposite diagonally), has a square form, and such form was expected, more than a round one. But the third and the fourth towers are not where they were supposed to be. They are located where nobody would expect them to be. Nobody, so the enemy either. Well, the third and the fourth towers are right beside the second tower; they form together almost the whole side of the castle – if they were four, then they would be the entire side of the castle, and the second and the fifth towers would be located in the corners. Now the corner is empty, towerless. Why? Due to some strategic reasons? To achieve an aesthetic effect (three towers in row and the towerless corner look better than four towers in row)? Or because of lassitude, lack of strength and imagination (no, don't blame the builder for that).... But it seems we know why the cluster of towers is located just there – from this direction usually hordes of destroyers arrive.
Not only this surprising cluster of towers proves the extraordinariness and bizarreness of Sand Castle. There is nothing inside it. There is nothing within the walls. Only the flat court. A landing field? For whom and for what? For armoured dragonflies?
There is no gate, either. Nowhere. Why?
There is no moat.
There is no road to the castle. This is logical: no gate – no road, and vice versa.
There are plenty of mysteries.
Yes. This is the real castle.
Full of mysteries. Mysteries are the most important in every castle.

And the areas of mysterious structures nearby. Fields of pyramids. Fields of mounds. Are they somehow connected and related to the castle?
Who defends the castle? Who are the defenders?
Who attacks the castle? Who are the expected destroyers?

A mystery is chasing a mystery.
Like waves.