An integrated, crack-free glass monolith is prepared via a modified sol-gel approach. It has an accessible network of channels consisting of anisotropic pores of widths ca. 20-50 nm and lengths ca. 100-250 nm. The glass monolith exhibits a transparency change based on humidity, which is utilized as a basis for optical humidity measurements. On the other hand, the glass monolith shows high proton conduction in humid atmosphere, and its proton conductivity reaches a value of 0.12 S cm(-1) at 30 degrees C and 80% relative humidity. (c) 2011 Elsevier B.V. All rights reserved.