The Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing has been operating the Visitor Center in Penteli since 1995. Its purpose is science education and public outreach aiming in particular at middle- and high-school students. This is accomplished through special seminars, talks, and observations with the historic 62.5cm Newall refractor in Penteli. The Center also produces educational movies on various astronomy related topics, which are presented to our visitors during the tours. The Visitor Center is also open to the general public during the evening at least four times a month. The evening tours consist of oral and video presentations, followed by a tour of the Newall telescope and observations, weather permitting. The Visitor Center is housed in the original building, with the 14m diameter dome, of the Newall refractor at the Penteli Astronomical Station, about 18 km from the center of Athens at an altitude of 500m. The telescope was commissioned by Robert Stirling Newall (1812-1889), a wealthy Scottish engineer and amateur astronomer for his private observatory in Ferndene (Gateshead). In 1890 the telescope was donated to the University of Cambridge and in 1957, to the National Observatory of Athens. The building, as well as the telescope, was fully refurbished in 2013. More than 200.000 people and about 6.000 schools have visited the Center since it commenced its operations.