When visiting Athens, naturally museums and archeological sites come first, with some general sightseeing on the side. However, not all museums charge entrance and there are several very interesting places to visit which are free, such as parks and various attractions. Diomidous Botanical Garden is located in the neighborhood of Haidari, on the road to Eleusis, with more than 2.500 different kinds of plants from all over the world. The Museum of Greek Popular Instruments, Foivos Anogianakis, in Plaka, hosts a collection of about 1200 Greek popular musical instruments which date from the 18th century. Visitors to Athens always enjoy watching the Changing of the Guards outside the Parliament on Syntagma Square and taking photos of the impressive ceremony. A visit to the Monastiraki flea market in Athens is a must, with a festive air on Sundays. At the National Garden, open from sunrise to sunset, children can play in the playground with swings and seesaws, or visit the children’s library while adults can enjoy the peaceful atmosphere. The view from Lycabettus hill is not to be missed. At the Museum of the History of Greek Costume visitors can admire the beautiful, elaborate costumes worn in the past. At the Athens University History Museum interesting facts about modern Greek history wait to be discovered. The Philatelic and Postal Museum is a paradise for stamp collectors. G. Gounaropoulos Museum is all about the superb work of this famous Greek artist.