90 Millimeter Observatory Return to Directory 90 Millimeter Observatory Category Observatories Address 14574 E 46th Ave Harleysville Pennsylvania 19438 USA http://www.90millimeter.org 267-516-2493 Contact Name Daniel B Acker Number of Members 5 Additional Information Backyard astronomy with small telescopes. Directions to listing From: Current location Specific Address Travel Mode: Driving Public Transit Walking Cycling