Adelaide's General Post Office is a colonial-era building in the Adelaide city centre. It is located at 141 King William Street on the north-west corner of King William Street and Victoria Square. The building was constructed in the period 1867-1872, and was the most expensive building constructed to that time by the colonial government in South Australia. Prince Alfred, The Duke of Edinburgh, was involved in laying the foundation stone. It is associated with several architects of note, including Edmund Wright, Edward John Woods, Edward Angus Hamilton and Robert G. Thomas. It was constructed from Glen Osmond and Glen Ewin stone, and ornamented with Bath limestone. The clock tower was officially named Victoria Tower by Prince Alfred on 1 November 1867 when he laid the foundation stone. The height of the tower was put at 154 feet, a little taller than the Albert Tower of the Town Hall on the other side of King William Street. The original plans had the tower somewhat taller, but R. G. Thomas was obliged to redesign it, as a cost saving measure.