The title says it all: if you've spent hours browsing the web for simple design icons for diagrams and architectural representation - a relevant tool to optimize organization, analysis, and communication - then this universal online library from The Noun Project will be very useful.
More than one million drawings generated by a global community are presented in the "Icons for Everything" gallery, which you can use by crediting the author through a Creative Commons license or paying a suggested amount for each design.
And why icons? They are a kind of universal visual language, an excellent form of direct communication for when words - or translations - are missing across the borders of the world.
Start your search here.