Under the deft direction of Mike Taylor, a leafy glade in Trinity College Gardens becomes the setting for Robert Louis Stevenson’s rollicking tale of pirates, parrots and pieces of eight.

Erica Gouviea's Jemima 'Jim' Hawkins' quiet world at the Admiral Benbow Inn is turned upside down by the arrival of Captain Billy Bones and his mysterious pirate chest. When tragedy strikes, Jim finds herself appointed 'cabin boy, er, girl' on the good ship Hispaniola, accompanied by handy treasure map and a motley crew thirsting for grog and gold.

There is much to enjoy about the Oxford Theatre Guild’s spirited production. Particularly successful are the ensemble scenes, where the actors relish the opportunity for physical comedy and the banter of Bryony Lavery’s script. Jonny Liron holds the audience rapt as the treacherously pleasant (or pleasantly treacherous?) Long John Silver. Special mention must also go to David Guthrie as the marvellously expressive Doctor Livesey, while Gavin Gaughan plays the terminally overlooked pirate Grey with fine comic understatement. Tobias Forbes is a fine captain of the Hispaniola (and has clearly attended the General Melchett School of Shouting).

Outdoor theatre can be demanding on the voice, and a central Oxford setting requires an even higher level of vocal projection. The cast do their best, though there is clearly much for them to contend with here – traffic, the odd helicopter, and the relentless sprinkler system on Trinity lawns. Not entirely out of place were the drunken roars from the direction of the King’s Arms – perhaps pub-goers could be asked to shout 'Grog!' to enhance the piratical atmosphere?

Some wonderful design touches include a versatile adventure playground-style set – including an accommodating person-sized grandfather clock. Some nicely choreographed stage combat ramps up the action sequences, while sound designer Tom Parfitt has worked hard to ensure his excellent effects enhance the production without becoming obtrusive. The use of puppets adds an interesting visual touch – also neatly resolving the conundrum of where to find a loquacious parrot willing to work for peanuts.

A most enjoyable evening, Treasure Island is a welcome addition to Oxford’s open-air theatre scene.

Last year's Love's Labour's Lost in Trinity College's gardens was staged on the grassy sward just inside the Parks Road wrought iron gates from 1713 whereas this Treasure Island on a warm evening of this Mediterranean summer inhabited a clearing just round the corner. The elaborate set by Anna Melson and four assistants reared up between a yew and a noble lime tree, all wooden platforms, boxes and stepped rails, its outlier scaffolding extending far into the latter. Trebling as the Admiral Benbow Inn, with the addition of a ship's wheel the deck of the Hispaniola, and then the eponymous isle itself, it was a triumph of labour and practical imagination – far in excess of what one expects of Oxford amateur drama. Congratulations to all of them.

This adaption by Bryony Lavery of R.L. Stevenson's 1881 novel, intended as a boys' adventure story, I believe remains pretty faithful to the novel, though I seem to recall from having seen the play in another version at the now sadly defunct Mermaid Theatre at London's Blackfriars in c.1962 that the opening Admiral Benbow scene was a deal shorter. Here I thought the scripted opening lacked a bit of zip, with rather laborious, occasionally shrill exposition and at this stage non-differentiated shady characters popping up. Some of this took place a little far back on the set, with consequent audibility problems (not helped by boy-racer motorbikes just over the wall thinking they were at the Isle of Man TT). Things looked up no end when Dr Livesey (excellent David Guthrie, a doddering Mr Woodhouse in 2016's Emma and now sporting a wonderfully booming voice) appeared and the narrative thrust itself into the finding of buried treasure with the forces of law and humanity in competition with desperate cutthroats fired by homicidal greed.

Director Mike Taylor and Movement Director Ophélie Lebrasseur (with assistants) had an arduous task on their hands with this long mini-epic, particularly tricky in the accommodating of up to 20 actors at a time on set and giving them something to do, and they were almost always successful in this after a slightly cramped, static time following the weighing of the Hispaniola's anchor. Indeed the whole energy level of the production ascribed a continuous, upwards curve; thus of the sword fights, the last between Long John Silver and Cpt. Smollett was the best, being ferocious and almost frightening. Hats off to Fight Choreographer Enric Ortuño. Also kudos to Lighting Designer Will Penington whose effective changes of colour as darkness melded with shadow mirrored the shifts in the struggle between goodies and baddies. The sound design was somewhat muffled; a bit more oomph might have helped. The period costumes were fine, though the pirates were surprisingly clean and spruce, and clearly one of their number was a trained barber!

From the cast, young actor Erica Gouveia in the long Jim Hawkins role grew and grew as the drama unfolded and by the second half was performing with seasoned ease. Her acting future looks bright. Jonny Liron's Long John Silver barked and postured manfully, but until the closing scenes I rather missed a keen sense of Machiavellian cunning and a sinister underlay extending to evil. As in OTG's Galileo, where he was the great man's student, Tobias Forbes was terrific in voice and stage presence as the irascible but principled Cpt. Smollett – I'm hoping next time to see him in a lead rôle. As Squire Trelawney, Tracey Rimell, so good in OTG's Festen in October 2016 was, alas, here miscast.

Of the pirates, Ruth Walker's Israel Hands babbled amusingly in perfect Portuguese, Daniel Taylor was a perky Dick the Dandy and Charlie Morgan bubbled with energy as Joan the Goa. Gavin Gaughan played a zany, enigmatic sailor with po-faced solemnity, and the first-class Ben ter Haar as Ben Gunn, the island castaway consumed by bitterness, conveyed a very well-judged mixture of pathos and naked revenge-seeking, backed by lots of simian movement on the ground and in the lime tree. And let's not overlook Magdalena Cheda's energetic and graceful work with the screeching parrot, Captain Flint!

Ambitious stuff from the OTG, not least in offering the spectator a final tableau of that finely-crafted set silhouetted against the shadowy trees and perfectly-lit in an orangey-brown light, with dim glades to left and right of it. It all but took my breath away.