Brother Brick

On the left side, a simple curved staircase connects the water level to the second floor, while on the right, a straight stair with a landing continues to the upper level sidewalk.

The official sets also include a Technic pin brick at the 10th stud in from each side to help the modules connect. We know from experience that, in practice, connecting dozens of modules with pins is often more troublesome than it is helpful, but we’ve continued that detail here just in case they’re needed.