Navigation in large and multi-scale virtual environments (MSVEs) is challenging, as users have to change their scale and then acquire spatial knowledge and scale information during their exploration process. Past work has presented wayfinding techniques for various multi-scale virtual environments, such as human body/biology MSVEs, astrophysical MSVEs, and town-sized to planet-sized MSVEs. However, there is no unified wayfinding user interface that can handle the whole range of possible MSVEs. Hence, this work focuses on the design and evaluation of a unified multi-scale navigation user interface to help users quickly understand spatial and hierarchical information in MSVEs, ranging from microscopic scales (< 10^0 ) through human scales (> 10^0 to < 10^7 ), to astrophysical scales (> 10^7 ). To achieve this goal, we first identify three kinds of hierarchical information that are essential for effective wayfinding in MSVEs: (1) linear size cues, to support common scale variations; (2) reference scale cues, based on human knowledge of objects in the world; and (3) power scale cues, which support exponential scaling. Based on this, we designed a wayfinding technique that integrates each kind of hierarchical information. Through a user study, we evaluated the developed technique and compared it to two baseline techniques for MSVE wayfinding. The results show that our technique can help users understand scale information, improve wayfinding efficiency, and that they prefer using it