The Timewheel (Hungarian: Időkerék) is a monumental hourglass located in Budapest, Hungary, adjacent to City Park, to the right of Heroes' Square and behind the Palace of Art (Műcsarnok). Constructed of granite, steel, and glass, the structure weighs approximately 60 tons. Its sand consists of glass granules that flow from the upper chamber to the lower chamber over the course of one year. On New Year's Eve, when the sand has completely emptied, the hourglass is manually turned 180 degrees by four operators pulling cables; the rotation, which takes about 45 minutes, resets the flow for the subsequent year.
The Timewheel was unveiled on 1 May 2004 to commemorate the 2004 enlargement of the European Union, which admitted Hungary and nine other nations. The monument was designed and built by János Herner following an architectural concept by István Janáky. It is notable for being one of the largest operational hourglasses in the world and serves both as a public artwork and a symbolic representation of the passage of time.