The UACNJ Observatory is located in Jenny Jump State Forest, near Hope, NJ. The observatory is open to the public on Saturday nights from April through October from 8:00-10:30 p.m. If you use the address 333 State Park Road, Great Meadows, NJ that should get you close to the driveway leading to the observatory.
From Route 80: Take Exit 12 (Route 521-Hope). From the off ramp go south on Rt. 521 towards Hope for 1.2 miles. Turn left at the light in Hope (there is only one). Then take the first right turn on Great Meadows-Hope road. Travel 2.4 miles to Far View Road. Turn left on Far View. The observatory entrance is 1.2 miles on the right (turn right just before the Jenny Jump State Forest sign).
From Routes 78-22: Take Exit 17 for Route 31 North. Travel north 16.6 miles (through Washington, and Oxford). At Route 46 (light at "T" intersection - Butzville), turn right. Go 5.8 miles on Route 46 to Great Meadows. Turn left on Hope Road (Route 611 - Saints Peter and Paul Church on corner). Travel 2.4 miles to Far View Road. Turn right on Far View. The observatory entrance is 1.2 miles on the right (turn right just before the Jenny Jump State Forest sign).