Most of these structures have been incorporated into the Flecker Botanical Gardens, a recreational precinct at the southern foothills of the Mount Whitfield range.

A stopping place, railway siding (for municipal quarry purposes) and shelter shed were constructed a Mt Islay at the three-mile in 1888–89, and was named Edge Hill.

In 1911 the line was moved 300 metres (980 ft) east to the other side of Saltwater Creek where a new Edge Hill railway station was erected.

[1] In 1940 about 10 acres (4 hectares) at Mt Islay, above the recreation reserve, again was gazetted as a municipal quarry, this time for land reclamation purposes.

[1] Early planning positioned the fuel installation behind wharf no.8 at the dockyards on Trinity Inlet, but as both the Australian and United States navies intended to expand warehouse storage facilities in this area, an alternative site was sought.

Two Australian Navy staff visited Cairns in late 1942 and approved a site at Edge Hill that could be camouflaged from the air and would be difficult for an aerial enemy force to attack.

This land had been leased privately prior to the war and two small buildings were demolished to make way for Tank 2, which lay on the former railway alignment.

Because these tanks were intended to hold dieseline they were constructed in plate steel, sourced from Broken Hill Pty Ltd.

Further excavation, including removal of a rocky outcrop, was undertaken during the second half of 1943 to create a level site for tanks 3–5.

Firstly the landscape was prohibitive and part of the hill had to be removed, with the core left for camouflage, before all five tanks could be constructed.

[1] After the war the Commonwealth removed the structures associated with the observation post on Mt Islay, but decided to retain the fuel storage tanks for their intended purpose.

The former WWII RAN Fuel Installation at Edge Hill is located 5 kilometres (3.1 mi) north of the original port of Cairns, in the foothills of the Mt Whitfield Range.

The installation, built into the side of Mt Islay, comprises five large fuel tanks (three in concrete, two in steel), earth and concrete bunds, two pump houses, a fire station (garage), foam tank and part of a disused railway embankment, located within three non-contiguous land parcels.

[1] Land parcel 346/RP711610 is located on the north side of Collins Avenue near the eastern entrance to the Flecker Botanical Gardens, on a former railway reserve.

The primary modification is the replacement of the roofing with "Spandex" cladding and the addition of a galvanised or Zincalume "collar" immediately blow the roofline.

[1] Land parcel 1/RP17796 is located on the south side of Collins Avenue, opposite Tanks 1 and 2, on part of the original Cairns-Herberton Railway alignment.

It contains two small former support structures associated with the WWII RAN Fuel Installation: a fire station (garage) and foam tank.

[1] The former fire station is located on the western side of this allotment close to the Collins Avenue road alignment.

The front elevation principally comprises three sets of double garage doors -one in the gabled section and two in the skillion side extension - opening onto Collins Avenue.

The tank is rectangular is shape, of pressed metal with a flat galvanised iron roof supported on timber framing.

[1] Land parcel 349/RP715416 is located on the north side of Collins Avenue approximately 500 metres (1,600 ft) west of tanks 1 and 2, on a former quarry site.

The fabric consists of heavy timber logs with oyster encrustations and industrial scale links and chain.

[1] A bund of formwork concrete about 1.5 metres (4 ft 11 in) in height extends along Collins Avenue for the length of the Tanks Arts Centre, overgrown with vegetation such as trees and orchids.

It is a small, single-storeyed building in rendered masonry, with a gambrel roof clad in corrugated fibrous-cement sheeting.

[1] A second foam shed is located in the south western corner of Lot 349 just outside the bund wall and facing Collins Avenue.

[1] WWII RAN Fuel Installation was listed on the Queensland Heritage Register on 2 February 2007 having satisfied the following criteria.

The installation is a rare surviving purpose-built WWII Naval fuel storage facility associated with the Pacific war and located in an urban setting.

Tanks 3, 4 and 5 contain high aesthetic values as industrial ruins in a heavily vegetated urban environment.

[1] The place has a special association with the life or work of a particular person, group or organisation of importance in Queensland's history.