Geoffrey Croft, president of NYC Park Advocates, described the worker as "traumatized" by his find, The Wall Street Journal reported. The man, described as being in his 60s, works in The Bronx.
Croft, who publishes a blog, A Walk in the Park, said someone also scrawled "KKK" in the bathroom at the facility, WPIX-TV, New York, reported. Police have said they cannot confirm the second incident.
The city settled a lawsuit in 2008 that accused the Parks Department of discriminating against employees who belong to racial minorities.