Art of Albrecht Dürer
The following drawings are by Albrecht Dürer (1471 to 1528).
This guy is amazing. A master of illustration book, probably the top 3 among all artists i admire. Also, consider his era. There are others of his era, such as Michelangelo, but their work i don't find attractive at all, usually a religious crap or flat or ugly shits.
Note the magic square on the upper right. The numbers sum to the same in any row/column/diagonal. The big blocky shape on the left is called a truncated rhombohedron. There are quite a few other allusions. of interest to math buffs. See: Melencolia I.