From Naef, the Swiss design company, Sphaera is an elegant hemisphere labyrinth crafted from cherry wood. Patience and dexterity are required to guide the two steel balls through the maze. This is a great gift for anyone who appreciates craftsmanship and the fine art of meditative puzzle solving.

Naef Circino - 17 semi-circular wooden elements in bold colors that can
be assembled either in their black frame or freestyle -  flat or stacked
upon each other.  Endless design and play fun with this sophisticated
set from Switzerland.  An elegant gift for the playroom, coffee table or
executive desk.

Naef Campanile - Ten different wooden elements, one tower. Solve the challenge by filling the tower. Multiple solutions in this spatial sense conundrum from Switzerland. This all-black version (except for the tower) is more challenging than the color version.

This "Precious Woods" version of "Naef Spiel" blocks uses one of the first designs by Naef company founder
Kurt Naef, and makes wonderful use of 8 beautifully grained woods. The sixteen blocks, each with 8 angled "teeth," can be
wedged and stacked together to form unusual, staggered creations, such
as bridges and towers, which can be built wider at the top than at the
base.  A stimulating, creative challenge for any builder, young or old.

Modulon is a classic Naef construction toy for the classic geometry fan.
 The sixteen rectangular shapes, in 7 varying sizes, and in bold
primary colors, plus black and white, are assembled in a cube which is
divided into the dimensions of the golden ratio.

Tectus is a classic Naef construction toy for the classic geometry fan. It consists of  23 white rectangular shapes, in several varying sizes, each of which is divided
into the dimensions of the golden ratio.  They are assembled in in black rectangular plates.