Horizons - Epcot - ended in 1999.
UK Horizons was created in 1997.
UK Horizons ended in 2004.
Horizons - Epcot - was created in 1983.
Reaching Horizons was created in 1992.
Burning Horizons was created in 1993.
Unknown Horizons happened in 2008.
Unknown Horizons was created in 2008.
A and O horizons
The incorrect form is "broaden your horizons" as there can only be one horizon. Edit from another user: There may only be one horizon, but that's hardly relevant in a metaphor. The common usage is "horizons," which is also what all the online references I checked say.
soil layers are called horizons
Soil Horizons