Athens is loaded with museums. It seems like there are new museums and branches of old museums opening every week. You can check the Athens News for traveling exhibits and this page will give you information on the main museums that should not be missed. An excellent book to get is The Museums of Athens by Aristidis Michalopoulos which is the most complete guide to Athens Museums that I have found. It contains opening and closing hours, entrance fees, and maps and descriptions on how to get to museums in Athens and Pireaus, the suburbs and nearby islands. Be sure to visit my History of Greece which will make visiting these museums even more meaningful.

National Archaeological Museum

The National Archaeological Museum ranks among the top ten museums in the world. Its impressive collection is housed in a beautiful neoclassic building near the juncture of Alexandras Avenue on Patission Avenue. There is a gift shop, and a cafe in the sculpture garden. Children under 6 and EU students get in free.

The museum is a five minute walk from Victoria Station and a 10 minute walk from Omonia. The Trolly #'s 1,2,3,5,6,7,8,9,11,13, and 15 all stop there.

Hours:
Tue-Fri: 8am-7pm
Mon:12:30pm-7pm
Sat, Sun & Holidays:8:30am-3pm
(there is an internet cafe right next door where you can send e-mail home)
See my Photo Tour of the National Museum of Archaeology
The Benaki Museum

Agia Sofias and Kouvari.
Tel 367-1000
Open Mon, Weds, Fr, Sat: 9 to 5
Thurs and Sun they close early.
Tuesday it is closed.
After at least 5 years of rennovations it is finally open again. Starting at the bottom floor with the ancient stuff and going up through the various periods of Greek history, my favorite part is the third floor and the heroes of the Greek Revolution and the birth of the modernb state of Hellas.  Just walk up Vass Sophias from Syntagma with the National Gardens on your right. Then you reach the end of the Gardens look to your left and that is it. The Benaki has opened two more branches in the area around Psiri on Agios Asamaton Street and on Pireaos Street.

The Goulandris Museum of Cycladic and Ancient Greek Art

4 Neofytou Douka St, Koloniki
Tel 722-8321 or 722-8323

This Outstanding collection of ancient Cycladic art is excellently curated. Open daily except Sundays and Tuesdays from 10am to 4pm.
Kerameikos Museum

148 Ermou
346-3552
Tues-Sun:8:30 to 3
Closed Monday

The ancient cemetery of Athens at the bottom of Ermou past the Monastiraki flea market has a nice little museum. The site itself though off the beaten path is one of my favorites. Lots of pottery and tombstones.  See Kerameikos

Museum of Greek Folk Art

17 Kydatheneon St Plaka
Tel 323-1577

Embroideries, wood carvings, jewelery, and other traditional folk art. The museums not-to-be-missed collection of ceramics is housed in a beautifully renovated former mosque at 1 Areos Street on Monastiriki Square. Open daily except Mondays from 10am to 2pm.

Jewish Museum

39 Nikis street at Kydatheneon in the Plaka
Tel 323-1577

Before the Nazi occupation and the decimation of Greece's Jewish population, many of Greece's Jewish communities traced their roots back to the Spanish Inquisition and before to Classical Greece. Art and artifacts from Jewish communities through the ages, as well as documentation of the Holocaust amkes this museum a cultural treasure. This museum was the creation of my 9th grade history teacher Nikos Stavrolakis. Opening hours: Daily 9.00-2.30, except Saturdays and Sundays 10.00-2.00

National Historical Museum

13 Stadiou street (in the old Parliament Building)
Tel 323-7617

This museum is perfect for those interested in the Greek War of Independence and it's artifacts. Open daily from 9am to 1:30pm. Closed Mondays. Free on Sunday.
    
Museum of Popular Musical Instruments

1-2 Diogenes St
Plaka
Tel 325-0198

This is my friend Groves Willer's favorite museum in Athens and I am inclined to agree with him. You can wander around listening to different instruments and styles of music through headphones at each exhibit.Open daily from 10am to 2pm. Wednesday from 12 to 6pm. Closed on Mondays. Admission Free. Visit John Marlowe's review at http://www.greecetravel.com/musicmuseum/index.html

Byzantine Museum

22 Vasilissis Sofias Ave
Tel 721-1027

A divine collection of Byzantine Icons, Mosaics, Sculptures, Bibles, Garments and more. Open Tuesdays to Sunday 8:30am to 3pm.

War Museum

2 Rizari Street and Vass. Sofias Avenue (next to the Byzantine Museum
Tel 729-0543

War implements from ancient times to this century including armor, swords, torpedos, and fighter planes. Photographs of various Greek campaigns and battles.Open Tuesday to Saturday from 9am to 2pm. Sunday from 9:30am to 2pm. Closed Mondays. Admission free.

Theatrical Museum

50 Acadamias st
Tel 362-9430

Greek theatre History. Photographs, programs, masks, costumes, posters etc. Open Monday to Friday from 9am to 2:30pm. Closed Saturday and Sunday. Admission free.

Greek Historical Costume Museum

362-9513
7 Dimokritou st, Kolonaki
Mon, Weds, Fri:10-1
Thurs: 5:30-8:30
Entrance Free