Table Mountain was inaugurated as one of the New Seven Wonders of Nature at a ceremony held at the foot of the mountain on Sunday morning, the City of Cape Town said.
Mayor Patricia de Lille thanked those who voted for the mountain last year to secure its place.
"Being listed as one of the New Seven Wonders of Nature will bring tremendous direct economic and socio-economic benefits to both Cape Town and South Africa," she said at the ceremony.
The New Seven Wonders Foundation's founder-president Bernard Weber said all South Africans should feel proud of the achievement.
He described the mountain as "a spectacular backdrop for Cape Town".
Table Mountain Aerial Cableway Company CEO Sabine Lehmann said the mountain had more visitors in November than in any other month in the past 10 years.
The other sites named as new wonders of nature are: the Puerto Princesa Underground River, the Amazon, Komodo Island, Iguazu Falls, Halong Bay, and Jeju Island.