The listening device, labeled “Air Defence Early Warning Listening Ears - 1917” on its short plinth, faces the Pest side of the river from its home at the foot of the Buda castle gardens. The device was used to amplify and monitor the sound of aircraft approaching the city during World War I.

Visitors can still don the headphones attached to the four giant listening cones and spin the steering wheels that originally helped fine-tune the direction the cones are pointing. Unfortunately, they won’t hear much these days.

The instrument is on wheels so it could be used around the city.