The Sechseläutenplatz, a 16,000-square-metre plaza near the city’s opera house, was resurfaced with quartz from the canton of Graubünden.
The development of an underground parking lot has allowed for the doubling of a largely grassy area that has traditionally been used to house the Knie Circus.
It is also the site of the traditional Sechseläuten celebration where the Böög, a symbolic effigy, is burned each spring to signal the end of winter.
This year’s ritual ceremony is set for next Monday.
Voters in September 2012 voted in favour of public financing for the rejuvenation of the plaza.
In her speech to mark its inauguration, Zurich Mayor Corine Mauch underlined the importance of the plaza as a meeting place and an area to celebrate freedom, the SDA news agency reported.
Swiss broadcaster SRF noted that 110,000 flagstones were used to cover the plaza.
The site, once a meadow, was protected as a public meeting place by Zurich city council in 1946.
The Böög has been burned there annually since 1904.
But for decades, the city did not to do with the field, which was used to grow potatoes during the Second World War, SRF said.
In the Middle Ages, the area was under water as part of Lake Zurich before being filled in.