This weekend more than 140 buildings across the city will unlock for Open House Melbourne, allowing you to explore unusual and culturally significant spaces usually off-limits.

Here are the little-known stories behind four buildings that will open their doors on Saturday and Sunday.

Horticultural Hall
31 Victoria Street, Melbourne

Henri L’Estrange, famed funambulist (tight-rope walker) and accident-prone hot-air balloonist, stitched his calico balloon inside Horticultural Hall before taking it over to the Carlton Gardens for his ascent into the Melbourne sky in 1879. The balloon ripped in a few places on the way over but the daredevil thought he would “chance it” anyway.

Filled with gas from Melbourne, which L’Estrange said was of higher quality than the Sydney gas he was used to, his balloon “shot up into the air with surprising velocity” to a height of around a “mile and a quarter” (two kilometres). As chance, or stupidity, or miscalculation would have it, the balloon exploded and L’Estrange was forced to deploy a silk parachute to slow down his descent. While most onlookers believed he would be “dashed to pieces”, he ended up hooked onto a fir tree at the back of Government House, rattled, but alive.

The Horticultural Improvement Society, which opened “Horti Hall” in 1873, was forced to rent its space to the likes of L’Estrange because it ran out of money during its construction.

Originally opened to advance agriculture in the colony, one wonders whether the society anticipated it would play a part in an aeronaut’s ballooning misadventure, or host weekly meetings of the X-Files fan club and Star Trek appreciation society, as it has also done.

Historian Susan Faine will fill you in on the colourful life of Horti Hall during her guided tours on Saturday and Sunday, which you can book here. At the time of writing it was unconfirmed whether the tours will conclude with a ride in a 19th-century, slightly ripped hot-air balloon.

Public Record Office Victoria, Victorian Archives Centre
99 Shiel Street, North Melbourne

The Victorian Archives Centre, inside the Public Record Office Victoria, is usually open to the public, but the team has pulled out all the stops for the Open House Melbourne weekend.

Rare documents relating to other Open House buildings – the Supreme Court, Substation J, and the Royal Australian Mint – have been pulled from the archives for rare public display.

Historical records for Frederick Bailey Deeming – executed in Old Melbourne Gaol in 1892 for murdering his first wife and their four children, and his second wife – will also be on display. To this day Deeming, who was born in England, is suspected of being responsible for the “Jack the Ripper” murders in London’s East End between 1888 and 1891.

The Public Records Office will be open on Saturday from 10am to 4pm. Book tickets here.

Grainger Museum
University of Melbourne, Gate 13, Royal Parade, Parkville

Percy Grainger was an Australian composer and concert pianist at the turn of the 20th century. Jo-Anne Cooper, manager of the Grainger Museum, says the precocious musician was a prolific collector and always wanted to open a museum about himself (don’t we all?). Although he lived abroad, he opened the Grainger Museum at the University of Melbourne in 1938 while in his fifties.

His Free Music Machine – a precursor to the modern-day synthesiser – was ahead of its time. It was revolutionary in its goal of achieving gliding tones, different rhythms and unconventional pitches through the use of oscillators. Measuring some seven-feet tall by six-and-a-half-feet wide, it looks like it is made from components scrounged from a tip. Although not in working order anymore, historical recordings from the device have inspired musicians such as Gotye, who is a frequent visitor to the museum.

Those with young children will also be familiar with Grainger’s composition of Country Garden, which The Wiggles have covered.

In addition to Grainger’s eclectic collection of photography, furniture, art, jewellery and costumes, there is a picture of his naked buttocks and the whips he used in his adventurous sex life. You’ll never listen to The Wiggles’ rendition of Country Garden the same way again.

The museum will be open on Saturday and Sunday, 10am–4pm. Bookings not required.

Victorian Artists’ Society
430 Albert Street, East Melbourne

The Victorian Artists’ Society was built in 1870 and some of Australia’s most cherished artists have passed through its halls. Arthur Streeton, Tom Roberts, Frederick McCubbin, William Dargie and Walter Withers were all members.

According to Anne Scott Pendlebury, who is a board member of the society, these esteemed artists all partook in gentlemen’s “smoke nights”. Always on a Friday night, these gatherings included the consumption of copious amounts of alcohol and cigars.

A convivial McCubbin was said to have sung Schubert at these events. The poems of Banjo Patterson and Henry Lawson, who were friendly with many of the artists, and who often paid visits, were also recited. Rumour has it that on several occasions members of the society brought back company from the nearby Little Lon red-light district.

Operatic soprano Dame Nellie Melba, whose conservatorium was a tenant of the society from 1898 to 1952, was known to have, on at least one occasion, given an impromptu performance from the balcony of the building to adoring fans on Albert Street.

Pay a visit to the building this Saturday or Sunday between 10am and 4pm and you can sing from the same balcony.

Open House Melbourne runs over Saturday July
 30 and Sunday July 31 from 10am–4pm at various locations.