What are the most worthwhile things to do in Perth on a first visit?

Kings Park, or Kaarta Koomba, is run by the Botanic Gardens and Parks Authority, a Western Australian state agency whose statutory functions include conserving native biodiversity and promoting the Aboriginal, colonial and contemporary cultural heritage of its parks. Inside it, the Western Australian Botanic Garden holds over 3,000 species of Western Australian flora, and the park contains 2 Threatened Ecological Communities — a remnant of genuinely wild vegetation inside a capital city. Its named features run from Fraser Avenue, the tree-lined entrance, to the State War Memorial, the Rio Tinto Naturescape, the Biodiversity Conservation Centre, the Saw Avenue Picnic Area and the May Drive Parklands. Together with Bold Park it draws over 5 million visitors a year.

Fremantle Prison is the heavier piece of the itinerary and the more surprising one. UNESCO inscribed the Australian Convict Sites in 2010 under Decision 34 COM 8B.16 and criteria (iv) and (vi), as a serial property of 11 complementary sites holding more than 200 elements between them, for what it describes as the forced transportation of convicts to British colonies, the forced labour and penal systems that went with it, and their part in colonial development. Fremantle Prison's own heritage account records that it was the first built environment in Western Australia to receive World Heritage listing, and that it had already been added to Australia's National Heritage List in August 2005. It was designed by Captain E. Y. W. Henderson, Comptroller General of Convicts in Western Australia, working from Joshua Jebb's Portland Works Prison; the final two-wing plan was approved in 1852 and construction was completed in 1859. It opened as The Convict Establishment and was renamed Fremantle Prison in 1867. The cells are stone, 7 feet by 4 feet, stacked 4 tiers high, and Henderson's original proposal was for 570 men — 240 in association rooms and 330 in separate cells. Britain legislated convict transportation to Western Australia in 1849 and ended it in 1868; the prison passed from Imperial to Western Australian control in 1886, with about 50 convicts still held, and closed as the state's primary maximum-security prison in 1991.

Rottnest Island, Wadjemup to the Whadjuk Noongar Traditional Owners, is managed by the Rottnest Island Authority under the Rottnest Island Authority Act 1987. It is 11 km long and 4.5 km across at its widest, holds 1,859 hectares of land and an associated marine reserve of about 3,800 hectares, and is described by the state as a Class A reserve. It has 63 beaches and bays, snorkel trails with underwater interpretive panels at Parker Point and Little Salmon Bay, and the Wadjemup Bidi walking network, which covers more than 45 km of connected trails and boardwalks.

The three places have very different grain. Kings Park holds more than 400 hectares carrying 2 Threatened Ecological Communities, so what you walk through is remnant vegetation rather than planting, with Fraser Avenue's line of trees as the one formal gesture. Fremantle Prison is stone and vertical: cells 7 feet by 4 feet, stacked 4 tiers. Rottnest is 19 km out in the Indian Ocean, and the state's own description sets the sheltered bays near the Thomson Bay settlement — The Basin, Geordie Bay, Little Parakeet Bay — against the bays towards the West End, which it calls rugged.

Fremantle Prison's listing is not a listing of Fremantle Prison alone. UNESCO inscribed 11 complementary sites as one property holding more than 200 elements, which is why the interpretation on site reaches well beyond Western Australia — Australia joined the World Heritage Convention in 1974, and the nomination partnership between the Commonwealth and the participating states and territories was only formed in 1995, with the Western Australian Cabinet endorsing it in June 1998. The site's own Crown Land vesting order, Reserve 24042, dates from 21 December 1993.

• Half a day, Kings Park — Over 400 hectares, 3,000-plus plant species and 2 Threatened Ecological Communities; Fraser Avenue is the orientation point.
• Half a day, Fremantle — The 1852-to-1859 construction sequence and the 1868 end of transportation are the substance of a tour.
• A full day, Rottnest — 63 bays and more than 45 km of Wadjemup Bidi trails do not compress into an afternoon.

Rottnest is a Class A reserve with no road connection, so a visit depends on ferry schedules and sea conditions, and the Authority's remit under the 1987 Act is to protect the island's flora and fauna as well as to run visitor facilities — expect restrictions rather than open access. Two of the three are substantially outdoors, and the Bureau of Meteorology's Perth Airport record gives an annual mean maximum of 24.7°C (76.5°F) against an annual mean minimum of 12.2°C (54.0°F), so an island day and a park day both want layers and a plan B. At Fremantle Prison the constraint is the building itself: cells of 7 feet by 4 feet stacked 4 tiers high mean stairs and confined spaces on any full tour.

The Perth when-to-visit answer gives the Bureau of Meteorology's monthly figures and the humpback window at Rottnest; the Perth food answer covers the Swan District wine zone and the state's rock lobster fishery.