Leca blocks that fit together through grooves?

[Mogg]

I've searched a bit online but haven't found what I'm looking for. Aren't there lecablocks with grooves on both sides for a better fit? There are grooves for reinforcement, but that's only on one side. I thought that in some lecablocks there should also be grooves where you could fit the blocks into each other.

Or am I completely wrong!?

 

[hagv]

http://www.weber.se/leca-registred-produkter/produkter/leca-reg-block/leca-block-200.html

Webers lecablock do have notches and grooves for better fit. Don't know about other brands though, it's Weber I've chosen for my upcoming extension.

 

[Mogg]

Was supposed to have them for the outer wall. Don't know if it was tongue and groove that I have in my memory.