There may be fewer workers, now or ever, returning to the Square Mile, but the sculptures have come. Launched in its 10th edition this week, London’s annual summer show Sculpture in the City has never been more welcome in bringing a sense of human scale and enlivening the monotony of high-rise glass and steel with colour, texture and idiosyncratic interventions at street level.

Starting at the Gherkin, I slipped into a cul-de-sac just behind St Mary Axe and met a quartet of abstracted gravel and limestone figures, a fraction taller than life-size and arranged in slight gradations of height, from the classically graceful to the lumpen, bumpy, indented and hollowed out. This is “Reactivity” by young Danish sculptor Regitze Engelsborg Karlsen.

The gossamer delicacy with which she handles earthy matter, the twin suggestions of geological remnants and the spirals and coils of fabric clinging to the body as in ancient Greek drapery, the rhythmic flow between the figures — all would be exquisite anywhere, but in the shadow of the Gherkin the organic shapes and tactile appeal are tremendously affecting.

If the city’s skyscrapers are emblems of dynamism, ambition and global identity, “Reactivity” stills time, and asks us to reactivate more contemplative urban encounters. She finds, and wants to offer, “a great calm in communication and being with physical objects and materials”.

After so long living virtually, a dominant theme in this year’s selection is our relationship with the material world, with urban grit particularly.

Several works spin art from junk. Tatiana Wolska cuts, perforates and thermo-welds recycled plastic bottles into elongated blood-red biomorphic forms sprawling through Leadenhall Market; they imply environmental catastrophe.

“Rough Neck Business” is Mike Ballard’s loosely geometric interlocking abstractions sourced from green hoardings from Olympic Park and blue ones from Hackney Wick. In the quiet garden of St Botolph’s churchyard, the horizontal clumps in Alice Channer’s “Burial” appear to be rocks, surreally stretched out to the length of a human body; in fact they are moulded from concrete remains gathered from London’s demolition sites, then cast in Corten steel — a palimpsest of the city’s shifting fabric.

Bram Ellens’ “Orphans” is a comic group of boulder-like, multi-angled ovoids, each constructed from scores of discarded paintings sourced from thrift stores and undertakers. Shown from the back as a field of imageless tacked-together planes, it is hardly a work to cheer a painter, though it celebrates a melancholy resourcefulness.

In a flair of placement, this stands on Cullum Street, in front of the stunning Art Nouveau Bolton House, dating from 1907. The artwork’s haphazard geometry plays against the building’s blue and white tiled facade, arched windows and lovely foliage frieze, rare and mesmerising in themselves.

Architecture is the bonus of Sculpture in the City: stopping you in your tracks, defamiliarising, inviting discovery, each work enters into dialogue with nearby buildings and, more broadly, with the city’s dense, eclectic medieval-to-Georgian-to-contemporary streetscapes.

Eva Rothschild achieves this marvellously with “Cosmos”, which stands by the back entrance of the Leadenhall Building (Richard Rogers’ “Cheesegrater”). Rothschild’s trio of aluminium slatted structures, spray-painted black on the outside, grading to purple, green, red within, lean into each another to form one unit “like a set of disruptive gates”, she says.

At three metres — human scale — “Cosmos” in this setting wittily condenses, repeats and varies aspects of the 225-metre Cheesegrater’s open/closed grid structure, slender tapered construction, ladder frame, steel bracings and coloured stripes, including the bright orange exposed lift racing up and down. In both the building and the sculpture, minimalism meets pop culture, sharp geometry is muted into enigmas of light and form, the fixed appears flexible, provisional.

Like most serious sculptors, Rothschild’s interest comes back to the body: “We inhabit ourselves quite fully when we encounter the physical artwork. It’s not about looking or projecting or storytelling. It’s about being present with an object that is equally taking up space,” she has said. It is also a lament for diminishing global space: “Cosmos” is a vision of a hemmed-in world, its elements coexisting in high tension. Rothschild’s presentation at the 2019 Venice biennale was called “The Shrinking Universe”.

Almuth Tebbenhoff expresses something similar in “RedHead Sunset Stack”: an irregularly shaped column, a mere outline, placed like a disembodied toy beneath Mitre Square’s dizzyingly high towers. Constructed in steel, coated in hot zinc and painted red, orange and pink, the “Stack” is a reminder of how far we are here from expansive sunset skies. Tebbenhoff instead abbreviates and abstracts the romantic sublime in industrial materials.

Casting “Stone (Butch)” directly from rock crevices at Godrevy Point in Cornwall, Roseanne Robertson brings the sea to the metropolis, summoning stone, water, landscape, body in a strange equilibrium of voids and solids, dark spaces in the margins and bright light. Something of the formal balance and robust fidelity to materials of Barbara Hepworth is here — they have been paired together at the Hepworth museum in Wakefield.

Robertson’s aim for this fluid figure — an uneven, lopsided shape in painted jesmonite poised on curving steel legs — is to reclaim “a natural space for Queer and Butch identity from a history of being deemed against nature”. Before reading this, however, I saw in “Stone (Butch)” not identity politics but a pair of wings, a musing on nature-versus-culture, an expression of freedom, flight, release.

This is altogether an optimistic exhibition, a treasure trail of small joys. Outside Fenchurch Street Station, “Bloom Paradise”, Jun T Lai’s giant painted lotus flowers, is a symbol of regeneration. Elisa Artesero’s poem “The Garden of Floating Words” (“You’ve Gone/ Touching Leaves in the Moonlight”), a blue neon levitating in the foliage of a small planter, is about enjoying a moment — ethereal, ephemeral.

None of the works in Sculpture in the City are here to stay, none are iconic statements; the pleasure is rather the unexpected interactions between works, places, people. In “Metal Man — Deeper Together, Deep Travel Ink. NYC”, Laure Prouvost’s “video heads” on metal-silhouette bodies wait to send out messages — “Come with us”; “This is the best thing you have seen for a long time” — to passers-by, distilling the general flâneur’s vibe.

It is wholly different from the experience of rural sculpture parks, where monumental pieces stand proud and bold against open skies, yet nature always wins and remains the chief attraction. Here in the beleaguered post-pandemic city, sculpture transforms, cheers and heals.

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