Athens Metro

 ( Electric Railways In Greece ) 

The system has five interchanges, at , , , and , allowing all three to interchange with each other at least once. Each line also has at least one connection with the Athens Suburban Railway, and the Athens Tram.

Line 2 is entirely underground. Line 1 is mostly overground, with an underground section spanning between the Monastiraki and Attiki stations, and an additional underground station (Kato Patisia) in central Athens. Line 3 is mostly underground; Trains that run an overground route are only those with the airport as final destination. The overground section of Line 3, east of the tunnel portal near , is open. In the tunnel sections up and down lines share a common tunnel, except for approaches to stations with an island platform (such as Egaleo). Rail yard are located at Attiki, Faliro, Irini, Piraeus, Kifissia and Thissio for Line 1, and Doukissis Plakentias, Eleonas and Sepolia for Lines 2 and 3.

The Athens Metro's three lines carried approximately 1,353,000 passengers daily in 2010.

A network map of the Athens Metro system, that includes the three current lines, the under construction line 4, the tramway, the suburban railway and all the future under design extensions.

The Athens Metro classifies rolling stock by "batch" for Line 1 and "generation" for Lines 2 and 3 because ISAP and AMEL used different classification systems for rolling stock before consolidation. Six types of rolling stock operate on the network, all equipped with third rail current collection systems; however, only seven second-generation trains have the necessary overhead line equipment to serve Line 3 from to .

The eighth batch (introduced in 1983) is the oldest rolling stock in passenger service, while the third generation (introduced in 2013) is the latest rolling stock in passenger service. The eighth- and tenth-batch stock is externally similar, but the former has split-flap headsigns in Johnston typeface and a cream-and-green interior colour scheme. An extensive refurbishment programme is in progress for the 8th batch (as of 2023), and to cover for trains undergoing refurbishment, up to five 1st generation Line 2/3 trains have been borrowed to operate on Line 1. Line 1 halfsets have driving cabs at both ends, unlike the Line 2/3 halfsets which have a driving cab at the outer ends, but only basic driving apparatus for shunting purposes only at the inner ends; thus, they can only operate on their own inside depots.

Lines 2 and 3 use the Alstom automatic train supervision system (ATS) and a passenger information system (PIS). Two-aspect red/white colour signals are used at points and junctions only.

**The Development Plan refers it as Line 4 branch but there are unofficial plans that this branch is part of the future Line 5.

If and when these projects are completed, the Athens Metro is expected to reach in length and serve a total of 110 stations by 2040.

The first phase of Line 4 will be between Alsos Veikou and Goudi stations, predicting fifteen (15) new stations and a length of of new track. An invitation to tender for the construction of the first phase of Line 4 was issued in September 2018. The construction started in mid to late-2021 and is scheduled to be completed in 2029 or 2030. The estimated cost for constructing the first phase of the new line is 1.51 billion EUR. Currently, the project of the first phase is considered to follow a PPP scheme which might be extended for constructing the whole new line. An alternative solution is a mixed funding between the EIB and the Greek State. It is also a high-profile candidate project to be included in the Juncker Plan of EU that will include also the second phase of Line 4 of Athens Metro.

The European Investment Bank is allocating a €730 million loan over 30 years to finance the building of the first segment of the Line 4 metro, which will connect Alsos Veikou and Goudi. The initiative will also assist Athens by reducing the number of private automobiles on the road by 53 000, resulting in 318 tonnes fewer CO2 released daily.

The Souflias plan was last revised in January 2012, and saw limited activity until October 2020, when Elliniko Metro announced that they were reconsidering some extensions from the plan, including the extension of Line 1 from to Nea Erythraia, the extensions of Line 2 to and Glyfada and Line 6 from Melissia to Perama. In December 2021, a part of the southern branch of Line 6 was reconsidered as a branch of Line 1 from to the SNFCC in Kallithea, with intermediate stations at Hamosternas, Plateia Davaki, and Lofos Filaretou.