The city of Budapest is located alongside the Danube, in the heart of the Carpathian basin.

The Budapest Metro was inaugurated on May 2, 1896; thus, it is the second oldest subway system in the world.

The original purpose of the first metro line was to facilitate transportation to the Budapest City Park.

 
Above is Andrassy Avenue, which became one of the most elegant roads in Budapest.It was recognized as a World Heritage Site by UNESCO along with the banks of the Danube and the Buda Castle Quarter in 1987.

Near the Deák Ferenc tér station there's a small museum for the Budapest underground system.
It was set up in an abandoned section of the MillFAV tunnel, which was cut off in 1955, when the construction works for the second subway line started.

Here we have an entrance to the "Millennium Line" subway at Vörösmarty Square, just outside the famed Cafe Gerbeaud.

This is not part of their subway system, but an interesting shot of the Budapest Castle Hill Funicular.