Ong Ewe Hai was a leader of Sarawak’s earliest Hokkien immigrants and the patriarch of an influential family – one of three powerful Chinese clans of early Kuching – that produced many prominent figures in business and politics. Around 1885, he spent an extravagant sum on the construction of a mansion on the hill on Wayang Street. The lavish, geomantically auspicious house overlooked the natural beauty of the Sarawak River and beyond, as well as the commercial triumphs of Ong, in the form of shophouses that lined what would later be called Ewe Hai Street. In front of the mansion was a courtyard enclosed by low walls inlaid with translucent jade green tiles. A Chinese-style horned archway stood at the entrance of the courtyard.
In 1933, descendents of the Ong family sold the mansion to the Anglican Mission for a few thousand dollars. The building, with a newly added third floor, became the boarding house of St Mary’s School. From 1968, it served as the diocese’s guest house. The Chinese-style arch was pulled down in the 1990s to accommodate a new road (the current Jalan Wawasan) connecting Wayang Street with Padang Merdeka. In 2013, the historic house was carefully renovated and converted into The Marian, a boutique lodging house.