In 1779 , she ordered detailed measurements and drawings of the monument to be executed .
By the late 18th century , however , the structure had so deteriorated that Catherine the Great was afraid to pass through the arch for fear of its tumbling down .
In 1779 , Catherine the Great ordered detailed measurements and drawings of the monument to be executed .
By the late 18th century , however , the structure had so deteriorated that Catherine the Great was afraid to pass through the arch for fear of its tumbling down .