The czar responded to the revolution of 1905 by

The Czar reacted to the Revolution 0f 1905 by promising to form  Dumas which were representative assemblies, to work towards reform.

On January 22, 1905, a group of workers led by the radical priest Georgy Apollonovich Gapon  had marched to czar Nicholas II winter palace in St. Petersburg to make their demands.

 Imperial forces opened fire killing and wounding hundreds. Strikes and riots broke out throughout the country in outraged response to the massacre to which Nicholas responded by promising to form the Dumas.

the structure was most likely used for;

c. playing a ball game with stone hoops