Optical instrument viewing around obstacles via mirrored tubes.
OpticsInstrumentMilitaryNavigation
Current best complexity is 5:
Periscope can be discovered in Concepts, categorized under Optics, Instrument, Military, Navigation. Optical instrument viewing around obstacles via mirrored tubes.
It has been discovered by 57 boards and crafted 302 times, first appearing 6 months ago. Periscope can be created from 106 recipes, and goes on to appear as an ingredient in 136 others.
Periscope was first discovered by Larry's board 6 months ago. They also hold the lowest-complexity recipe, at 5.
Related concepts worth exploring include Scope, Telescope, Marine, Binoculars, Rainbow, Fleet, and 6 more.