Isleworth Ait

Isleworth Ait, Hounslow

An unspoilt nine-acre island in the Thames, located off Old Isleworth at the mouth of the River Crane

Hidden London: The Thames at Isleworth Ait by Stefan Czapski

Rows of ancient stakes have been found at the south­ern end of Isle­worth Ait. These were at first inter­pret­ed as some kind of for­ti­fi­ca­tion but they were more prob­a­bly the rem­nants of tidal fish traps, which have also been exposed on the near­by main­land fore­shore.

A Roman legion is said to have wad­ed west­ward across the Thames via the ait in 54bc – and then head­ed north to car­ry on con­quer­ing. How­ev­er, the Romans are said to have done a lot of idio­syn­crat­ic things in the Lon­don area at this time, often (as in this case) with very lim­it­ed sup­port­ing evi­dence.

In the 17th cen­tu­ry there were four aits here but their divid­ing chan­nels have since silt­ed up. Osiers were cul­ti­vat­ed for their flex­i­ble twigs, as they were on sev­er­al Thames aits.

This was for­mer­ly part of the Syon Park estate of the dukes of Northum­ber­land, who per­mit­ted a rudi­men­ta­ry swim­ming pool to be built here for the use of local chil­dren in the mid-19th cen­tu­ry, but noth­ing of this remains.

Isle­worth Ait is now a nature reserve man­aged by the Lon­don Wildlife Trust’s Houn­slow group on behalf of own­ers Thames Water. Beneath the high canopy of mature sycamores, poplars and wil­lows there are hawthorns, hol­lies and elders, sum­mer snowflakes and marsh marigolds. The island’s fau­na range from tree-creep­ers, king­fish­ers and herons to bats, but­ter­flies and some rare snails (specif­i­cal­ly the Thames door snail and Ger­man hairy snail). In order to pre­serve the habi­tat, pub­lic access is dis­cour­aged – but the trust occa­sion­al­ly organ­is­es super­vised vis­its.

Human activ­i­ty is per­mit­ted at the water’s edge – despite the objec­tions of some res­i­dents oppo­site – in the form of a float­ing boat­yard and dry dock. The dim­ly sun­lit yard is vis­i­ble in the cen­tre of the pho­to­graph above.*

Postcode area: Isleworth TW7
Bing bird’s eye view: Isleworth Ait
* The picture of the Thames at Isleworth Ait on this page is adapted from an original photograph, copyright Stefan Czapski, at Geograph Britain and Ireland, made available under the Attribution-ShareAlike 2.0 Generic Licence. Any subsequent reuse is hereby freely permitted under the terms of that licence.