Never heard of it? How about the Longworth Institute, Longworth House, or as the old Air Force Club, in Scott Street, in the inner-city, not far from Newcastle's former Newcastle rail terminus.

Dating back to 1892, the facade of the building is extraordinary, looking like it's been transplanted brick-by-brick from Europe.

With its ornate Anglo-Dutch facade of red pressed brick with elaborate carved sandstone features, it is Newcastle's most baroque building.

According to the State Heritage Office, the building is of modest proportions but is of "outstanding aesthetic significance" executed by an architect of national importance and it's one of the few examples of this style remaining in Australia.

Not far away is another extraordinary building, the former David Cohen & Co warehouse, in Bolton Street. Decades ago it was slowly being demolished, but was saved and converted into the building we know today as the Bolton Street carpark.

Both landmark buildings were designed by the same man, a German-born architect called Frederick Bernhardt Menkens (1855-1910) who came to call the Hunter his home. He designed 28 impressive buildings in Newcastle in his lifetime, among more than 100 structures in the Hunter Valley.

Menkens also designed a new town hall for Newcastle. The massive colonnaded structure would have covered a whole city block near what is now Market Square on the Hunter Street Mall.

His entry won the competition, he was paid the prize but the building was never constructed. However, many of Menkens' buildings have survived to become true landmarks.

The man himself was one of Newcastle's most colourful characters, a hard-working bon vivant who loved horse racing, gambling and a drink or two (Menkens died of cirrhosis).

Think of Laman Street above Civic Park and the iconic Baptist Tabernacle and St Andrew's yellow brick church (both from 1889) - you're again looking at the work of Menkens. A Lutheran from birth, Menkens became the great architect of the Catholic Church for 17 years in the Hunter Valley, designing churches from Cassilis to Wollombi.

But his unique architectural masterpiece, at least from the so-called "decorative" phase of his life's work, was designing his wonderfully baroque Wood's Chambers at 129 Scott Street, city.

This same iconic building, today called Longworth House, is now for sale with expressions of interest closing on March 12.

Given a rebirth in 2000, it was further restored internally in 2009 as a function centre and tapas bar. Containing four separate entertaining areas, this elegant building with its oriel windows, polished timber floors, Kurri-pine ceilings, French-inspired ballroom and two lounge bars is being offered for sale as a restaurant/bar, wedding and events venue or even as a unique residence.

When it started life in 1892, Wood's Chambers was designed as a business centre but then became a cultural and social hub of Newcastle. Menkens was instructed by liquor merchant Joseph Wood to make a wine auction space with "superior" office accommodation to rent. Menkens liked his creation so much that he carried out his practice from the first floor of the building from 1893 until his retirement in 1908.

Later, the Longworth family bought the site and it became a cultural centre with an art gallery, a library and concert recital hall.

In March 1928 the building was gifted to the Australasian Society of Patriots by benefactor William Longworth - it was commonly referred to as The Empire Club.

The ASP members also believed Newcastle's European discoverer Lieutenant John Shortland RN landed in the vicinity of the site in September 1797 and even put a plaque up to this effect on the facade, but the jury is still out on that claim.

From 1946 the Air Force Club made its home there but decades later it became vacant and fell into disrepair before restoration began in the late 1990s by Suters Architects.

Brian Suters was one of two architects (the other being Les Reedman) who has long had a fascination with Menkens.

"His work was his life," Suters told an audience at a lecture inside Longworth House several years ago. "This building's a treasure. Menkens put his heart and soul into it and it had lots of innovations, including a glass roof and lead in the floors to deaden the sound between floors."

Menkens was also a perfectionist, helped by working for years at trades.

Suters said Menkens once also went to jail on a matter of principle. Menkens had designed the tower at historic Jesmond House (near the Obelisk) and believed a Sydney electrical contractor was trying to hoodwink him by installing silver instead of platinum electrodes on a lightning conductor.

Menkens was sued and lost, but then refused to pay four shillings ($4) in damages awarded against him, so was sent to jail for 12 months. In Maitland Gaol he then set up his practice to keep working uninterrupted on his ideas. His jail term coincided with a severe economic depression in the 1890s, so in a sense he came out of it on top.

Today the legacy of Menkens also lives on in Scott Street about a block west from Longworth House. Here, inside a cleverly converted former warehouse are the Menkens Apartments. The original structure was designed by Menkens in 1899. Inside the foyer is a large framed photograph of Menkens and his pampered pooch, Mick, along with more pictures and memorabilia.

According to Newcastle historian Keith Parsons the 1899 building replaced the R.Hall & Son City Produce Store, which burnt down in 1895. "People might remember this old warehouse better though as the site of clothing firm Rundles. They left, the building was converted and these apartments opened in 1998," Parsons said.

And what of the rare books held in the Longworth Institute library? One story is they survived, stored by a collector for safekeeping in a disused refrigerator ringed by chains and padlocks in a suburban garage.