Langmuir monolayers constitute a powerful platform for self-assembly and organization of amhiphilic molecules. Controlling the structural features of condensed domains formed within Langmuir monolayers, however, is a challenging task. The formation of remarkably diverse condensed microstructures is demonstrated in binary monolayers comprising of a surfactant (octadecylmelamine) and a diacetylene monomer. The mole ratio between the two con-stituents and composition of the aqueous subphases (specifically pH and which dissolved metal ions are present) dramatically modulated the shapes and dimensions of microstructures formed at the air-water interface. The selfassembled microstructures could be transferred from the water surface onto solid substrates, and subsequently further served as templates for gold coating, yielding electrically conductive microwires.