Wandering among voluptuous stone hermaphrodites and miniature pregnant nudes, all clustered in the thick juniper and pine forest of Can Ginebreda, you might be forgiven for thinking you had stumbled into an x-rated fairytale. This is no ordinary stretch of woodland. Scale one of the forest's peaks and you'll pass a sensuously carved abstract named Genesis, resembling a concrete vagina giving birth. Get to the top and a towering giant is impaling himself on his own penis. It may sound like something dreamed up by Hans Christian Andersen's deviant twin, but in reality the "bosc d'escultures" (sculpture forest), situated north of Girona in Catalyuna, is the brainchild and life's work of Catalan artist Xicu Cabanyes.

Can Ginebreda is named after its abundant juniper trees – ginebrer is Catalan for juniper - but it's the sculptures that attract around 100 visitors a week to the privately owned park. Cabanyes has been amassing an ever-increasing collection of his own work here since the 1970s, and the forest is now home to more than 100 different pieces.

When we arrive, the artist himself is pottering around his workshop in the forest grounds, baroque music playing in the background, a pack of good-natured dogs lolloping about nearby. Stockily built, puffing on a pipe, with small square glasses and a firm but friendly manner, Cabanyes comes here every day to continue working on his various collections, and is remarkably casual about letting visitors roam through the open-air gallery. "Take as long as you want, go where you want. We close when the sun goes down."

It's clear to see that harmonising his art with the natural surroundings is a key part of Cabanyes's vision. Many of the older stone and concrete pieces have acquired a stealthy layer of moss or lichen, rooting them to the earth. Near the entrance, a stone cup perched on a penis stem has collected muddy looking rainwater, likening it to a pagan font. In another piece, Head of Medusa, made in 1980, the head emerges from the ground, but 28 years of rainfall and corrosion has submerged most of the statue in a small pond, and now only the top of her face floats ominously in the water. Sinuously carved concrete and stone pieces are designed to catch and ferry rainwater though their various channels.

Perhaps the reason Cabanyes integrates his art so closely with the landscape is that he has always been at home in this region. Born in 1945 in the nearby town of Serinyà, he found himself, aged 16, working in a carpenter's workshop, where his interest in the world of carving first took hold. Later, he began to experiment with stylised earthenware figurines and metal. In the 70s he played a key role in founding two artistic collectives in the Banyoles area, which, as well as organising local conferences and exhibitions, also contributed to the popular anti-Franco movement. Cabanyes has since gone on to exhibit his work around Spain and Europe.

Although many of the exhibits in the forest have an erotic undercurrent, some have a darker feel. Take for instance Txernóbil (Chernobyl), a monument built from gigantic empty bomb shells, with a sea of large pebbles scattered at its feet, some carved into distinguishable skulls, some left smooth and faceless. There are abounding references to death in many of the works, something which Cabanyes feels is strongly linked to the erotic.

It's clear from the number of Catalan press clippings pinned to the workshop wall that the park is well known locally. Further afield its popularity is spread mainly by word of mouth. But not all visitors come away satisfied. According to Cabanyes, the open-air gallery has attracted its fair share of critics, in his experience, mostly English.

But dwell too long on the art's serious side and you'll miss Cabanyes's roguish sense of humour. As we are leaving the workshop, he points to a mural of human bottoms on its outer wall, all moulded from cement.

"These were modelled from life. All friends." He gestures in among the derrieres to where oxidised iron crosses jut out at aggressive angles. "Do you know why I put those crosses there?" he asks. I flounder. "It's easy", he says, pointing to the place on each bottom where the vertical crack meets the horizontal line beneath the buttocks. "There is a cross in everyone." And with that, he summons his pack of lively hounds, jumps into his pickup truck and speeds off, leaving us to enjoy the sunset in this strangely enchanting forest.

Getting there

Can Ginebreda bosc d'escultures is reachable by car, just outside the picturesque town of Banyoles in the Porqueres region, about two hours' drive north of Barcelona. Take the AP-7/E-15 heading north from Barcelona until you pass Girona, then C66 to Banyoles. Finally, the Carretera de Mieres (GE-524) towards St Miquel de Santmajor leads you straight to the left-hand turn off for the forest. Road signs begin to appear once in Banyoles.

Entrance to the park costs €3 (£2.38), canginebreda.com (website in Catalan)

Easyjet flies from London Gatwick to Barcelona from around £60rtn