Diamond Hill, Mountain in Connemara National Park, Ireland

Diamond Hill rises 442 meters (1,450 feet) above sea level with quartzite ridges offering views of the Atlantic Ocean and the surrounding Twelve Bens mountains. A circular walking route accesses the summit and lower sections of the peak.

The mountain closed in 2002 due to erosion damage on its slopes. It reopened in December 2005 after substantial restoration including wooden boardwalks to protect the surface.

The Irish name Binn Ghuaire most likely refers to Guaire Aidne mac Colmáin, a 7th-century King of Connacht who died in 663 and was known as "Guaire of the extended hand" for his hospitality. He is the title character of W. B. Yeats's play The King's Threshold and is linked to Dunguaire Castle near Kinvara. The anglicised forms Bengooria and Benhoowirra also appear.

Two trail sections allow visitors to choose based on fitness level: a shorter lower loop and a steeper upper route to the summit. Bring waterproof clothing and sturdy walking shoes as weather changes quickly in this exposed location.

The Discovery Map prints the name as "Diomond Hill", a spelling Paul Tempan notes is not used locally; the usual form refers to the glitter of quartz crystals on the mountain. The Irish name Binn Ghuaire links the peak to Guaire Aidne mac Colmáin, king of Connacht, who died in 663.