The gateway was erected as an entrance to the former Palace Garden by Bishop H W Majendie in 1812.

The Palace Garden was replaced by the Bible Garden, which was designed by Dr T Whitehead and opened in 1961. At the time it was said to be unique in Europe, possibly in the world, because 'all the plants directly relate to Biblical subjects such as the Passion Flower and "St Peter's Keys".'

Cadw describes the gateway as: 'Coursed rubble gabled gateway with parapet and stepped buttresses flanking 4-centred archway surmounted by iron tablet with Bishop’s mitre, dated 1812 and initialled H B (Henricus Bangoriensis). Double iron gates cast by Mersey Foundry, Liverpool. Similar iron plaque to inner side with attached lamp holder (lamp missing), Short sections of crenellated walls to either side.'

It's Grade II listed because of it's 'group value with St Deiniol’s Cathedral and the Old Vicarage.'