Greece's Parliament, built between 1836 and 1842 by Bavarian architect Friedrich von Gärtner, was originally a royal palace. On 3 September 1843, the constitution was declared from the balcony of this palace. In 1935, the palace became the seat of parliament. If you're interested in history and politics, you can take a guided tour of the building a few months of the year. To do so, make sure you reserve your spot at least five days in advance.