Among them is Dunedin's very own Ravensbourne Rd, where a good 50m stretch of hillside is retained by a substantial series of rock cages.

The website describes these cages, otherwise known as gabion baskets, as a "bad art school project about industry versus nature". Yet flick through some of those home and garden magazines (which do have photos prettier than any you'll see at uglynewzealand.com) and you'll find similar edifices increasingly being used in domestic contexts these days.

However, Wanaka landscape architect Georgina Pinckney urges a little caution for those contemplating incorporating into their garden layout a wall structure more commonly used by roading engineers: gabion cages, often with a 1m-deep profile, might dominate the very landscape they were meant to enhance.

"I find the proportions of gabions can be quite broad and overpowering. You are also stuck with quite a definite style that you might not be able to change later.

"Another thing to think about is the fact that a wall is, generally, quite an expensive structure and a reasonably permanent structure so it needs to not date.

"Stone walls have been round for hundreds of years, while block and plaster walls can be changed with a lick of paint."

When it comes to walls, a key consideration is how best to complement a house and garden. Often, landscape designers attempt to mirror the structure of a house in the landscape.

"That's why it's important to use similar materials and proportions," Ms Pinckney says.

"Walls might have windows or shutters in them; they may have panels with gaps so it doesn't completely wall you in.

"My main choice with anything to do with landscaping - but particularly to do with walls - is to try and use an element that already exists in a building. So I probably wouldn't use schist walls unless it was used in a building. If it was a block and plaster house, I'd try and use the same in a wall.

"It's about trying to minimalise as far as introducing new materials. But you also have to be careful because if you use the same materials, it might be too much. You might introduce something complementary that doesn't take over, that allows the house to become the focus. It depends on what you're trying to draw the focus to, really," Mrs Pinckney explains.