Tate's Cairn, Mountain summit in Sha Tin District, Hong Kong.

Tate's Cairn is a 583-metre peak on the Kowloon Ridge inside Ma On Shan Country Park. Its main summit holds a Hong Kong Observatory weather station, with a government radio station on the eastern sub-peak and a police post to the west. The 3.95-kilometre Tate's Cairn Tunnel runs beneath it, linking Siu Lek Yuen and Diamond Hill.

The mountain first appeared on colonial maps during the 1860s and was named after George Passman Tate, a surveyor who mapped Hong Kong in 1899. This early cartographic work was part of British efforts to survey the newly acquired territory.

Locals call this summit Tai Lo Shan or Big Brother Mountain, and it marks a transition point between two sections of the MacLehose Trail. The mountain serves as a meeting point where hikers change directions on their longer journeys.

The summit is accessible via Sha Tin Pass Road, with MTR service to Wong Tai Sin station and minibus 18M providing access to the trail. The route is popular on weekends and clear days, so starting early helps avoid crowds.

The summit's weather radar is not a temperature and rainfall observatory: Hong Kong Observatory installed the territory's first weather radar here in 1959, a Decca 41 X-band set with an exposed antenna. Rebuilt four times, the station received Hong Kong's first dual-polarization S-band Doppler radar on 8 October 2015, able to distinguish hail regions and raindrop sizes.