What was built in moscows red square by tsar Ivan the terrible?

In Moscow's Red Square, Tsar Ivan the Terrible commissioned the construction of St. Basil's Cathedral in the 16th century. Completed in 1561, the cathedral is renowned for its unique architectural design featuring colorful onion domes. It was built to commemorate the capture of Kazan and symbolizes the unification of the Russian lands. Today, it remains an iconic symbol of Russia and a UNESCO World Heritage Site.