During Rome's birthday or Natale di Roma, lots of people gather outside the Pantheon to witness a light show which has been happening annually for centuries owing to Emperor Hadrian who is believed to be responsible for the construction of the Pantheon. One interesting event at this time is the sunshine that passes through the Pantheon's oculus which can be observed annually at noon on April 21. Other entertainment includes massive reenactments of the history of Rome, like the story of Romulus and Remus and famous battle scenes. These events take place at the Circus Maximus and other locations. Reenactments attract thousands of participants from different countries as well as hundreds of thousands of spectators.