English inscription:

To the memory of the victims shot into the Danube by Arrow Cross militiamen in 1944–45.
Erected 16 April 2005.

And some context from Wikipedia:

The Shoes on the Danube Bank (Hungarian: Cipők a Duna-parton) is a memorial erected on 16 April 2005, in Budapest, Hungary. Conceived by film director Can Togay, he created it on the east bank of the Danube River with sculptor Gyula Pauer to honour the Jews who were massacred by fascist antisemitic Hungarian militia belonging to the Arrow Cross Party in Budapest during the Second World War. They were ordered to take off their shoes (shoes were valuable and could be stolen and resold by the militia after the massacre), and were shot at the edge of the water so that their bodies fell into the river and were carried away.