These blocks are fantastic - really high quality and big enough that you can really do architectural magic with them. If your kids have a brio train set, don't buy any of those expensive add-ons, get these instead - and you can build your own bridges / tunnels / stations / cities with them (see pic). My son loves to build our house at one end of the room, a train track, then London at the other. I don't know why there haven't been more reviews of these, just take a moment to have a look at the 200+ (not joking!) five-star reviews on the US amazon site (amazon.com) - 'nuff said!