Tourists visit the Schonbrunn Palace, in Vienna, Austria, May 16, 2020. As one of Vienna's most famous attractions, the Schonbrunn Palace reopened on Friday after the country eased COVID-19 restrictions.

Tourists visit the Schonbrunn Gardens, in Vienna, Austria, May 16, 2020. As one of Vienna's most famous attractions, the Schonbrunn Palace reopened on Friday after the country eased COVID-19 restrictions.

A tourist visits the Schonbrunn Gardens, in Vienna, Austria, May 16, 2020. As one of Vienna's most famous attractions, the Schonbrunn Palace reopened on Friday after the country eased COVID-19 restrictions.

Tourists are seen in front of the Schonbrunn Palace, in Vienna, Austria, May 16, 2020. As one of Vienna's most famous attractions, the Schonbrunn Palace reopened on Friday after the country eased COVID-19 restrictions.

Tourists visit the Schonbrunn Gardens, in Vienna, Austria, May 16, 2020. As one of Vienna's most famous attractions, the Schonbrunn Palace reopened on Friday after the country eased COVID-19 restrictions.

Tourists visit the Schonbrunn Gardens, in Vienna, Austria, May 16, 2020. As one of Vienna's most famous attractions, the Schonbrunn Palace reopened on Friday after the country eased COVID-19 restrictions.

Tourists are seen in front of the Schonbrunn Palace, in Vienna, Austria, May 16, 2020. As one of Vienna's most famous attractions, the Schonbrunn Palace reopened on Friday after the country eased COVID-19 restrictions. (Photos: Xinhua)

Two wagonettes await visitors in front of the Schonbrunn Palace, in Vienna, Austria, May 16, 2020. As one of Vienna's most famous attractions, the Schonbrunn Palace reopened on Friday after the country eased COVID-19 restrictions.

Tourists visit the Schonbrunn Gardens, in Vienna, Austria, May 16, 2020. As one of Vienna's most famous attractions, the Schonbrunn Palace reopened on Friday after the country eased COVID-19 restrictions.