These awesome lego-style wooden bricks are produced by Mokulock, and available through White Rabbit Japan. They are made entirely of maple and birch woods and are compatible with existing lego bricks. A set of 50 pieces costs 31 USD.
I am really tempted to order some; they look so well-made and intricate.
However, Mokulock has a disclaimer that says “the pieces can warp or fit together imprecisely due to the nature of the material in different temperatures and scale of humidity…” How would they fare in the tropics?