Ondřejov Observatory is the main observatory of the Astronomical Institute of the Academy of Sciences of the Czech Republic, which is also home to it. It is situated on the outskirts of Ondřejov, 35 km southeast of Prague, at an altitude of about 500 m. The observatory was built in 1898 by the amateur astronomer Josef Frič, who donated it to the Czechoslovak state in 1928. In 1967, a two-meter mirror telescope was installed at the observatory, at the time being the 7th largest telescope in the world. It is still the largest telescope in the Czech Republic.